Here are the comps I have owned, with reviews below: (last updated April 13, '08)
If you don't want to read through all these reviews, click here for a quick answer about which ones I like best.
I used all of these with a variety of active and passive bass guitars, and some of them I also used for synth or line-level audio. My testing rig for these reviews includes Canare cables, a high-quality DI into an Ashly LX308 mixer, through a set of Beyerdynamic DT990 or DT770 headphones. The DI's/preamps I have used include the Summit Audio TD-100, Phoenix Audio (UK) "Nice DI", Radial JDI, Phil Jones Briefcase, and Ampeg SVP-CL. It has been pointed out to me that the Beyerdynamic phones have a spike in frequency response around 20 KHz, so I have been hearing noise/hiss that many people will not hear through their speaker cabs. I consider that particular "inaccuracy" a good thing though, as it means that my descriptions of hiss will be relevant to recording engineers, and it also means that if I say a comp's noise is "moderate" or "not bad", that noise will probably not be noticeable at all under most real-world performance circumstances. Most of my reviews describe how noisy or quiet each compressor is, and I test and listen carefully for that aspect; but it's important to understand the causes of noise- different equipment, rooms, and wiring can cause a piece of gear to be noisy for one person and quiet for another. Please click here for more on that subject.
I typically spend at least three hours, over the course of a few days, working with each compressor. Some units are easy to understand and master within that short period of time, but some others require a lot more exploration, study, and studio time before I feel I have understood their secrets well enough to review. There are some of these units which I have worked with for over a month before reviewing, and many more which I reviewed in a shorter time but where I had to go back later and edit the review as I learned new things about each unit.
Conneaut Audio Devices CGM-2: This is a two-channel line-level rack unit that also features a noise gate and an expander. It has a nice crisp sound with no rolloff of lows or highs. It's a bit noisier than some other rack units, but it's not bad- mostly noticeable with heavier compression settings, when it will "pump and breathe". There are no glitchy artifacts when you cross the threshold, and the action is quite smooth. The controls for the compression are limited compared to other rack units, but the range available works fine for bass. The gate and expander are not so useful for bass, but they work well enough and would be handy if you wanted to also put this unit to other uses such as drum overhead mic busses. I would say it is useful and decent if you can find one for cheap.
MXR Limiter: This red box (with attached AC cord) from the late '70s/early '80s is the smoothest and cleanest-sounding pedal from that era I have tried, a real hidden gem. Most of the "vintage" comp pedals you see on Ebay are noisy, lose highs or lows, and squash your tone; but this MXR is very transparent, smooth, and especially low-noise. It imparts a bit of softness to the sound, taking the edge off the highs and the boom out of the lows, so it's a very natural and even sound but it will not suit users who want aggressive or boomy tone. Otherwise the signal is remarkably uncolored. In spite of the "Limiter" label it seems to work best as a gentle compressor for general signal smoothing; it doesn't actually do a very good job of limiting sharp spikes. If you need to use it for that purpose though, I got decent results by setting the attack and release at their fastest settings. Note that the attack knob turns clockwise from fastest setting to slowest, but the release knob goes "backwards" from slowest to fastest. The envelope is very smooth, and it is easy to forget that this unit is switched on. The footswitch is not "true bypass", but the bypass is excellent and clean. Note however that the signal is boosted above unity even in bypass, so you may need to adjust your other gain stages.
MXR Dual Limiter: I picked up this rack-mount unit because I had heard that certain record producers liked its raunchy tone, and I dig compression as an audible effect. Well, the tone IS raunchy, too much so for it to be usable 90% of the time. This is a killer unit to have tucked away in your studio, for its unique gritty sound, but most bass players would hate it. Most notably, the note decay is choppy and un-natural. There is added noise and weird changes to the envelope. Think of it as an "instant lo-fi" grunge effect, not a normal bass comp.
Custom Audio Electronics V-Comp: This is an amazing little unit. It uses a single preamp tube, and if you turn the threshold down it can be used as a tube high-gain booster! I tried a few different tubes in there, but the stock GT actually sounded best. This comp adds a noticeable darkness and thickness to the tone. But otherwise, the envelope is very natural, and you wouldn't notice it as an effect. Like most tube devices it can pick up some noise from your pickups and room wiring, but overall it's surprisingly quiet, especially on the decay. There is no audible noise swell. For over a year I picked this one as the pedal I would leave on just about all the time. Overall this is one of the most nice sounding and useful compressors I have tried. I ended up selling it because the note attack could get a little mushy in conjunction with the tube preamp I was using, but it's the perfect tool for warming/fattening a solid-state preamp. The interior of the box is very densely packed with components- Electro-Harmonix should check this out and take a few notes about efficient use of space. The footswitch is true bypass. Update: It looks like this pedal is no longer available for sale in the US, at least not from Tonefactor (who were the distributors previously), so if you see one for sale, grab it up! They are still available in Japan.
HHB Radius 3 Fat Man: Another tube compressor, but this one is rack-mounted. I can't give it a thorough review, because frankly I barely used it. It is three rack spaces high, and a half-rack width, so it didn't fit at all in my rack. I remember it sounded great when I first plugged it in, with very full and clear tone, but the form factor meant it just sat at home in the box. So I suppose it would be great for a home studio, but not much else. One very nice feature is that it has a hi-z input so you can plug your bass straight into the front panel.
BBE MaxCom: A two-channel line-level rack-mount unit featuring a gate and a "Sonic Maximizer" function. It sounds quite clear and full-range; with the maximizer switched off, it is pretty much free of any noise or tonal coloration. With the maximizer on, you can really bring up the punch and shine of the low and high end; use it sparingly, though, as too much maximizer can sound phony and harsh. The gate is OK, but not subtle, and prone to stuttering at the threshold. The knobs, switches, and plastic jacks all feel wiggly and flimsy, so it probably can't take heavy road usage. The other problematic feature is the "link" button, which doesn't seem to work at all. Overall I really like the way this thing sounds on my stereo mixes, but I don't trust it as a dedicated bass unit. Some people have noticed that higher settings of the maximizer will scoop the mids, so be aware of that while EQ-ing your rig.
Ibanez CP9: I found this one to bring out a lot of brightness in the tone; unfortunately it rolled off some of the low end. Its compression was very musical, and the brightness was nice sounding (kind of sparkly). The variable attack rate is a good feature, and the envelope is fairly even. There was a noticeable "noise swell" as the note decays. Mostly this is a set-it-and-forget-it unit that imparts some brightness, but has a fairly transparent and smooth tone and action. Overall though I didn't like it on bass because of the noisy decay and the low end rolloff. The footswitch is not true bypass, but the bypassed tone is relatively clean.
Ibanez UE 303B: This is an old analog multifx pedal, featuring an envelope filter, a chorus/flanger, and a compressor/limiter. It was made for bass, and the comp section is essentially a CP-9 adjusted for bass frequencies. It's got a punchy, beefy sound- somewhat dark and warm, but not muffled. The threshold knob is "backwards", in that the "low" marking is the highest threshold, and the "high" marking is the lowest threshold; if you turn it up to "high", the entire signal is squashed. As with many comp pedals, increasing the compression also increases the noise quite a bit, especially on the swell as your note trails off. But at lower settings, the noise is quite tolerable. The killer envelope filter and the chorus are the real reasons to buy this unit, but the compressor works and sounds pretty nice for a vintage pedal, especially at gentle settings. The high compression settings sound awesomely powerful, though, if you can tolerate the noise! The footswitches are not true bypass; if you just disengage the individual compressor switch, the "bypassed" signal still has a dark quality, but if you disengage the "master" footswitch the bypassed tone is clear.
Barber Electronics Tone Press: This is an interesting pedal, it works very differently than most other compressors. It has a blend knob, which allows you to blend the compressed signal with the uncompressed signal, without any changes to your overall level, or any phasing issues. It retains the low end very well, and the blend function is seamlessly smooth. It is designed to be a completely transparent processor, meant to go un-noticed. And it does that very well, up to a point. The thing is, it totally raises the noise floor as your note decays, even more than the Ibanez units. So the sound is pristine and pure, until you let a note sustain, and the hiss rises up to meet you- it sounds to me like the tide coming in. I guess that will not bother many players, especially if they dig the other good qualities enough, or if they play with not so much sustain. I wasn't having it though, I found the changes in noise level distracting. The footswitch is true bypass.
dbx 163X: This is a half-rack unit, and it has inputs for both line level and hi-z (instrument level) signals, which is quite handy. It only has two controls, so operation is very easy. Note there is no bypass switch. The tone is fairly uncolored, the noise level is actually quite low, and the action is moderately punchy. Unfortunately, the lowest and highest frequencies are a little bit attenuated. Also, while the compression is good and smooth, it doesn't limit sharp peaks. These show up pretty cheaply on Ebay all the time, so if you just want a decent rackmount unit for cheap, this one will do the job fairly well.
dbx 160A: This one is an "industry standard", one of the units most widely used in professional PA racks. It's a one-channel, line-level only, one-rack-space unit. To my ears, honestly, it doesn't sound that much better than the old 163X. It's not bad at all- the noise level is low, and the compression is quite smooth and free of unpleasant artifacts. It's got a very punchy action, great for rock and any sort of aggressive music. But the lows are not as full sounding as I'd like, and there is a little rolloff of the highs, especially at stronger amounts of compression. The controls are quite easy to use, while still offering a decent range of comp action. I can totally understand why this model is so widely used: it sounds good enough for general purposes, it's built tough, and even a monkey could find decent settings on it. I would recommend it to somebody who wants a rackmount that is very simple, clean, and reliable. But it doesn't quite measure up if you want to hear huge-sounding low frequencies or bright clear highs. In my opinion the older 160 XT is a bit better sounding overall.
dbx 166A: This is another one-rack-space line-level unit, but it has two separate channels and extra features such as gating, expansion, and peak limiting. I directly A/B compared it to the 160A, with identical input signals, and I strongly preferred the 166. I felt that it had even lower noise, a better low end, and the "contour" function allows an even bigger bass sound by making the compressor less sensitive to low frequencies. The highs were about the same between them, in other words pretty decent but not awesome. The highs seem brighter at lower comp ratios, and more damped at higher ratios. Otherwise the sound is super transparent, one of the most "invisible" comps you could hope for. It is also quite versatile, with a wide usable range of tweakability to dial in exactly what you need. I also was able to set the 166 to sound and compress pretty much identically to the 160A and the 163X. The gate/expander works fine, but it is not subtle. I would definitely use it on stage, but in the studio I would pick a more unobtrusive gate. The peak limiter, unfortunately, does not seem to do anything at all; and, overall I'd say this unit is better at general compression than it is at sharp peak limiting. Of course the flip side of all the controls available is that it takes some effort to find the right settings. It is not as easy to set up as the two or three-knob units, and there are no presets. The "contour" function is interesting: if your bass has relatively even output levels across high and low notes, engaging the contour will give you a bigger, bassier sound, which sounds really good. However if your bass (or playing technique) puts out big loud spikes in the low frequencies, you want the compressor to control those spikes, so you would switch off the contour in that case. All in all, this unit knocks my socks off for the punchy clean sound, low noise, and versatility, especially considering they can be found fairly cheaply on the used market.
Carl Martin comp/limiter: It is capable of a wide range of compression settings, from totally smashed-out slow squeeze, to mild compression, to sharp "hard knee" limiting. It offers more controls than most pedal comps: Threshold (the volume level at which it kicks in), Comp (the ratio of compression), Resp (response, which affects the speed of the attack and release, as well as the knee), and Gain (post-comp makeup gain). This is definitely one for the knob-tweakers, and patient listeners. People who want to plug-and-play will be frustrated by this pedal, as it requires quite a bit of tweaking to get the setting that works best for your setup. I got this unit mostly wanting to use it as a limiter to keep my tube preamp from clipping. Unfortunately it turns out that the maximum limiting setting still allows some sharp peaks through- it does limit, just not quite a "brick wall". Also, at max settings your tones can have an artificial sound to them until the limiter lets go, and there is sometimes a little "pop" artifact when the limiting engages. Where this unit excels is clean, non-extreme, "natural" compression. At more moderate settings, this unit is smooth and transparent. The sound is surgically clean, but rather dark, as it does seem to roll off some highs. There is no added noise at all at unity gain with moderate settings- this is easily the quietest comp pedal I have ever "heard". If you turn the output gain up higher than unity, though, it can add noise. I would recommend this pedal very highly to someone who wants crisp transparent sound and the lowest noise, as long as they don't mind the learning curve and the dark tone. The footswitch is not true bypass, and your tone stays the same (highs rolled off a bit) when the pedal is switched off.
Boss CS-3: I had seen this guy "Humphrey Mods" advertising on Ebay for a little while, and the reviews I'd seen of his CS-3 mods were very positive, so I decided to take a gamble. What he does is he takes a Boss CS-3 and replaces a number of the components for wider frequency range and lower noise, and replaces the red LED with a larger blue one. I popped the hood, and it's pretty clean in there. There were only three or four solder points that looked a bit unprofessional, but they are solid. Regardless, this pedal has a very smooth, natural action with almost no artifacts. It actually does a fairly good job of clean peak limiting, as it uses a high compression ratio. Also, many pedal compressors tend to roll off the highs a bit, but this unit has a tremendously clear full top end, and can even boost the highs slightly. I set the Tone knob to about 3:00 for a snappy clear tone with no rolloff. The Attack knob offers a wide spread of attack-time options. The tone and action of this pedal reminds me a lot of the old Ibanez CP9, only with better sound quality. It emphasizes the higher harmonics and restrains the volume of the lower ones, so your bass has more "bite", but less "oomph" at the bottom end. So it would not be suited to somebody who is all about the massive lows, but it will definitely help you cut through the mix. This pedal mod is NOT as noise-free as Humphrey and other reviewers claim. However at modest Sustain settings (like 10:00 or lower), the noise level can be low. But as with most comps, when you turn up the sustain for greater squish the noise increases quickly. This pedal is capable of extreme squish, if you can handle the accompanying noise. At all settings it does have the slight "swell" of noise floor when your sustained note trails away, but it's not so noticeable at lower Sustain settings. I have spent a silly amount of money on compressors in the last couple of years, and so far this one is seriously competing with all of them for day-to-day usability. The footswitch is not true bypass, but the bypassed tone is fairly transparent. >>Note: You'll get better bass response by replacing the input capacitor with a higher value. Humphrey doesn't seem to want to do that mod, so you'll need to do it yourself. I like a .22uF or larger cap at the input. The stock CS-3 is very noisy, it loses a lot of low end, and it is prone to distortion. In my opinion, the CS-3 needs to be modded to be usable on bass. Here is a link to the mods.
Electro-Harmonix White Finger: Man, this pedal was a disappointment. On the one hand, the range and quality of compression styles and tones is amazing -from the funkiest squish EVER, to subtle transparency- but the noise level at all settings is ridiculous. They should have named this model the "White Noise". I wanted to love this pedal, the compression is so awesome and full of character, but the noise was just unacceptable. If you're in a loud funk/rock band and can handle the noise though, I think you'd dig it. I like that even though this thing has more controls and options than most pedal comps, it's actually pretty easy to find good-sounding settings- I didn't have to painstakingly hunt for the right settings the way I did with the Carl Martin. The footswitch is true bypass.
Electro-Harmonix Black Finger: Well I finally broke down and got a Black Finger, after several people said I was really missing out. Unfortunately, I can give the exact same review of this one as I did of the White Finger: great sounding squash, with too much noise. It hisses like a basket of snakes, and I've read a number of other reviews saying the same thing. Note however that I've heard from a few people that their Black Finger is not noisy at all, so it's possible that there are both "good ones" and "bad ones" on the market, luck of the draw. I blame EHX's poor quality control. Aside from that issue the compression is thick, fat, greasy, funky, and versatile. It sounds very similar to the White one, there is not much of an audible quality difference between the tube and solid-state versions. The Black one has one really cheesy element: there is a little light bulb between the tubes, to light them up. Because I guess consumers need their tubes to light up like a reading lamp in order to show that they paid extra for something with tubes. The footswitch is TBP. I intend to get ahold of a Black Finger that is claimed to be non-noisy, to hear it for myself. If it's true, I'll update this review.
JangleBox: This is a neat unit, not actually intended for bass- it was designed specifically to give guitars the bright jangley tone and shimmery sustain heard in tunes by the Beatles, the Byrds, Tom Petty, the Pretenders, etc. I liked the idea of bright shimmery upper harmonics on bass tones (especially fretless), so I had to try it. The good news is that the tone really is killer, and very full-range. It seems to add rich fullness and shine to the tone evenly from the highest notes to the lowest. It is capable of both subtle and extreme compression (high Gain settings squish a lot like an Orange Squeezer), and it retains the note attack nicely. It also provides a terrific amount of added sustain. The bad news, once again, is the noise. The Janglebox and the Black/White Fingers just slay me, because they would be the most awesome-sounding compressors ever if it weren't for all the noise. After a couple hours of experimenting, I found the setting that gave me the best signal-to-noise ratio (gain 1:00, attack 9:00); ...if on a loud stage, or using a cab with no tweeter, that would have been an incredibly nice tone. But with a tweeter, or through headphones, the noise level was still way too high. And the very long sustain is accompanied by a serious incoming swell of hiss. The pedal has a switch for Dark, Normal, and Bright tones; the Dark setting does roll off most of the noise, but it also rolls off enough of the highs to essentially cancel the whole point of this pedal. For comparison, the Humphrey CS3 gives just as much of a chimey bright tone, with noticeably lower noise, and it was half the price. The only things the Janglebox does better than the Humphrey are longer sustain and fuller/warmer low end. I guess it's up to the user to decide if they can work with the noise to achieve these tones (it might really be worth it depending on your setup). I was able to improve the s/n ratio somewhat by turning down the gain knob on the pedal and turning up the input gain of the amp after it. The footswitch is true bypass. The construction quality overall is really quite good, but there's one thing to note: the DC power jack is center positive (the reverse of most Boss-type jacks), so any ground noise from other center-negative pedals (like tremolo clock noise) may be audible through this pedal unless you put it first in the audio chain.
Guyatone TC-X: This pedal contains a 12AX7 tube. Guyatone discontinued these a few years ago; they made a bass version as well, called the BC-X, but I rarely see those for sale, so when one of the TC ones showed up I snagged it. Out of the box it did indeed lack a little bit in the low end, but I fixed that by changing the input and EQ capacitors. This pedal is another one for the knob twiddlers, with many controls. It requires some patience and experimentation to find the right settings, particularly because a couple of the controls are not self-explanatory and the instruction sheet doesn't help any. I actually had to email Godlyke (the US distributor) to find out exactly what the "shape" knob does. The controls include: "Comp" which is the amount of compression; "Shape" which blends the compressed signal with the uncompressed original signal (to retain more of your natural note envelope); "Attack" which controls the attack of the compression; "Level" which controls the output volume; and a stacked pot labeled "Level" and "Freq" which is a sweepable-frequency active mid boost. The tube in this pedal does not provide any grit or overdrive on its own. The overall tone is thick, warm, and dark. There is some treble rolloff. There is also a noticeable noise floor, which increases as you turn up the Comp knob. This is another pedal which would be awesome except for the noise. But as with the JangleBox, you may find the fat tone to be worth it anyway. Especially because of the active mid-shift EQ, which is a potent tone-shaping tool much like an active bass preamp. The footswitch is not true bypass, but the bypassed tone is quite clear and uncolored.
EBS MultiComp: This is an excellent unit! It has very low noise, and turning the compression knob up to higher settings does not increase the noise at all. The "normal" and "multi-band" modes are clean and transparent, however they can also sound sort of boring or dry. But the "tube sim" setting adds a nice thickness and boost to the mids, and has a rich tone; it does seem to roll off the highs just a bit. In the other two modes there is not much rolloff of highs or lows, although it is not quite as "boomy" or "bright" as some other comps. The tube-sim mode sounds great for both fingerstyle and slap, at any Comp setting from 12:00 to max, and I could happily leave it switched on all the time at that setting. But don't ignore the multi-band mode! If you set the compression to max in the MB mode you can get a very articulate and defined slap sound. The maximum compression ratio is only 5:1 however, so it is not much of a peak limiter for the very aggressive players. The attack of the compression is a bit slow (and not adjustable), so it allows your natural initial attack spikes through, which can be good or bad depending on the rest of your gear- it's great for a more articulate or aggressive sound, but those sharp attacks can clip your amp momentarily. But the compression itself is very smooth and natural. High-output active basses can distort the EBS very easily. It has a switch labeled "active" and "passive"; you would think that choosing the "active" setting would solve the distortion problem, but it seems to me that the active setting does nothing but add a lot of hissy noise to the signal and doesn't reduce the distortion at all. I am getting the best results with the EBS set to "passive" regardless of the bass. So if you are getting distortion, do two things: turn down the output level of your instrument, and open up the EBS to adjust the internal trim pots. Turning the pots clockwise lowers the threshold, meaning the compression will kick in at lower signal levels. In MB mode, each trim pot ("high" and "low") adjusts the threshold independently for high and low frequencies. In the Normal and Tubesim modes, the "low" trim adjusts the threshold for the whole signal, and the "high" trim is not active. In Normal and Tubesim modes, with a high-output bass, I'm getting the cleanest results with the low trim pot turned to max (fully clockwise). In MB mode however, having the low trim at max results in too much compression of the lows, causing a weak and thin low end. So for MB mode I'm getting the best results with the low trim at 12:00 and the high trim at max. Again, this is with a high-output active bass; your results and settings will vary depending on the output level of your instrument, and how much you want your signal compressed. You may find that raising the threshold (trim pot counter-clockwise) helps you get a more "natural" sound. When I used a passive P bass I got good-sounding results in each of the modes without adjusting the trim pots at all. The footswitch is not true bypass, but the bypassed tone is quite transparent.
Toadworks Mr. Squishy: This is a variation on the Orange Squeezer circuit, and you can definitely hear the typical "dip and swell" of the Squeezer. However this one gives you more control over the effect than other Squeezers, allowing much less "noticeable" compression if you want. Where this unit really shines is in the way it does NOT add any coloration at all to your tone, and remarkably has a very wide frequency range- it does not roll off the highs at all, and it doesn't lose any of the lows unless you have the Gain knob set to maximum. The noise level is about average- not the worst, but not great either. Unlike most other comps, the noise level does not change much with different compression settings. The "Squish" knob reminds me of the "bias" control of other Squeezers, which changes the character of the compression as much as the amount. Depending on how you set the Squish, there can be more or less of the "dip and swell", and you can control what the note attack sounds like. Some settings will cause an artifact like a light "pop" with each note attack. This can be cool as an effect, but could also be annoying; good thing you can dial it out as needed. This comp is good at controlling peaks, adding a tad more sustain, and being effect-y squishy if you like. It doesn't do "punchy" though, pick something else if you want an aggressive punch. The input Gain control is great for matching this pedal to the output of different basses. Gain at max can get you some buzzy overdrive (not actually good sounding IMO), and at minimum Squish levels this pedal can be used as a nice clean boost. I see these guys selling used for around $80 USD, and they are an excellent buy for that kind of price. I am a little bit disappointed about the noise floor, but otherwise you get very clear full-range tone and an interesting compression action. The footswitch is true bypass, and the pedal seems ruggedly-built.
Ashly CL 100: This is a half-rack-width unit, and it takes only line-level input. Ashly makes clean-sounding, professional, no-BS equipment, and this is no exception. It has completely uncolored, transparent sound with no loss of highs or lows, and very little noise. It does take some time and experimentation to find the right settings, but it is capable of a very wide usable range of compression and limiting. The only complaint I might have about this unit is that it doesn't add any magical fatness or sparkle to the tone. It can even sound sterile or "dead" at certain settings. But find the sweet spots, and it lets your natural tone come through with no alteration or artifacts- especially notable when set up as a limiter. I wish they hadn't discontinued this one, and I wish it was in pedal form, but the plus side is that they sell for cheap when they show up on Ebay.
FMR RNC: The "Really Nice Compressor" is a 1/3rd rack space unit that runs at line level only. It's very popular, lots of reviews say it is one of the best compressors available at the price point. That may possibly be true for stereo mixes, but I really found it lacking for bass. It has some good points: the lows and highs are not notably rolled off, and there is almost no noise at all. But it distorts far too easily, and not in a good-sounding way. FMR makes it very clear on their website that the RNC is capable of unusually fast release times, which will cause distortion on low-frequency material. Fair enough, but I tried slow settings, as well as just about every other possible setting, and got distortion with most of them. Especially when I had it set up as a limiter, there was unpleasant glitching whenever the signal hit the threshold. I fully understand that FMR intentionally designed this unit with a much wider range of release times than most other comps in order to provide the most creative freedom to users; however the unfortunate result is that the majority of possible settings for this unit are not usable with bass. I also found that the good settings, when I eventually found them, were very finicky- when I changed instruments, or changed playing styles, I had to spend another age trying to dial in another usable setting, which got tiresome. I ran some stereo music through it at light/moderate settings, and the results were clean and nice; but it took so much effort and compromise to find good settings for bass guitar that I can't recommend it at all for that purpose.
Presonus Bluemax: This is a 1/2 rack unit that's packed with a lot of features for the small size. It has a full set of controls -attack, ratio, release, etc.- plus a bank of presets for all kinds of applications like bass, keys, vocals, and so forth. These presets are actually quite usable, I would be content in many instances to just use the bass preset with no adjustments. There are also two "effects" presets for extreme compression, and they are both very cool sounding and different. The tone is not notably colored, and the action has a very wide range of qualities depending on the settings. The lows are actually quite full and strong, but unfortunately the highs have a bad rolloff. Also, the noise level is a bit higher than I'd like. If you mostly play the deep roots sounds like blues or reggae, this is a super versatile comp with a really big sound, and will serve you well. But if you like a bright tone or upper end clarity, you might want a different unit.
Boss LMB-3: This limiter pedal works and sounds much better than I expected. I have just spent a fair amount of time directly comparing it with several higher-priced comps, and the LMB-3 was almost as good as any of them. The lows are nice and full, and the highs are clear and present, although the overall tone is kind of dry, and not "fat". The noise level is very low. The compression ratio has a full range available, so it can be used for mild to extreme squashing. It is a limiter primarily though, it won't add noticeable sustain. There are only two downsides to this pedal that I have found so far: First, there can be an audible "pop" or "click" artifact each time the limiting threshold is crossed, notably with higher ratios or harder playing. It is a small sound, that might not be audible in a full band mix, but it honestly would infuriate a solo jazz artist. Second, the "enhance" knob is, just like the ones on many amp heads, actually a "suck" knob. It scoops your mids and adds a lot of hiss. You'll want to leave the enhance turned off completely. I really wish Boss had given this pedal an "attack" knob instead. But aside from those two gripes, this thing is pretty good- all the more so when you realize they sell for around $50 used on Ebay every day. It's good enough to use on a pro gig, no problem, especially in a rock band. I imagine it might sound even better with some modding. The footswitch is not true bypass, but the bypassed tone is clean.
Demeter Compulator: Everyone says this is one of the best comp pedals available, and for once I have to agree with everyone. This unit is stellar. It has an excellent frequency range and very low noise. The compression action is smooth and natural, with no unwanted artifacts. It also presents a lot more "energy" in the low end than many comps. In fact, that perceived energy or tonal richness in the low end is missing with a lot of comps I've tried, and it is one of the qualities that can really make or break your tone. This is one of the few comps I've tried that actually does "fatten" the signal. The Compulator also does a fantastic job of adding sustain without adding too much noise. Most other sustainers are way too noisy. If I was to search for something to complain about with the Compulator, it would be the limited controls (only two knobs), so there's not much variety of action from it. It is designed to sound only smooth, not aggressive. OTOH, it is extremely easy to use, so the two knobs are as much of a plus as a minus, depending on what you like. This pedal is the dream unit for fingerstyle soloists and EUB players. It has better highs than the EBS MultiComp, but is less versatile. Also the Demeter is capable of stronger peak limiting than many other pedals, so it is excellent for players who have an aggressive technique or who use an envelope filter that puts out big spikes. The footswitch is not true bypass, but the bypassed tone is transparent. Another thing to note is that the DC jack takes a tip-positive 1/8" male plug, not the standard Boss type, so you'll need a special adapter in order to use most power supplies; also it seems to operate with much lower noise using a battery instead of an external supply. This is one of my favorite pedals.
Aphex Punch Factory: This is a very popular pedal, as it is inexpensive and, as reviewers are quick to say, very transparent. It is indeed remarkably transparent, and has no rolloff of highs or lows. It is also a very subtle compressor; I think too subtle. One of the ways I test compressors is to watch the meters on an outboard mixer while I play or run sound. Watching the meters while using this pedal, I could see that very little compression was happening until I set it to relatively high settings. I could also see that the meter on the PF was registering a significant dB amount of gain reduction, much more than I could actually hear, or see on the outboard meters. I found that I couldn't really register noticeable compression until the "drive" was cranked up to at least 7. However, as with most comps, the higher the compression level, the higher the noise at unity gain. And even with drive at 7, the PF did not do much to limit stronger peaks, for example from slapping. Cranking drive to 10 had more noticeable compression, but also much more noise, and at that level it sort of kills your tone. Well, subtle compression is good, right? Lots of times, a good comp is expected to be "invisible", and people are encouraged not to compress signals too heavily. But the PF is so subtle, and so poor at anything other than subtlety, that it is almost not worth putting it in the signal chain at all. The lower "drive" settings sounded basically the same as when it was switched off, and looked the same on the meters, no matter what the meter on the PF claimed. So while the PF really is as amazingly transparent as people say, it's not so good at compression. As far as the construction, the jacks are plastic and they are secured only to the circuitboard, not the housing, so every time you plug or unplug you're putting strain on the circuitboard. Update: the unit I used was not true bypass, but apparently they have changed over to TBP switching on the newer units.
ART MDM-8L: I'm only reviewing this because I happen to have it around; it's not something you'd use in a bass rig. This is a rackmount limiter with eight completely independant channels, intended for use in multitrack digital recording. Each channel has its own in/outputs and controls, and can be stereo linked with an adjacent channel. There is both a compressor circuit and a peak limiter per channel, but the only controls are threshold and output level, so it is not very versatile. A certain amount of the limiting and comp functions are "program dependant", automatically varying based on the signal coming in. The "MDM mode" switch sets all of the output levels to the same setting. This is a terrifically quiet and transparent processor, and it does its comp/limiting job very well, with natural smooth action and few artifacts. The highs and lows are not as bright or full as I'd like, but they aren't bad at all. All in all, if you need an easy-to-use comp/limiter for your multi-channel setup, this one does a great job, quiet yet effective.
Retro-Sonic Vintage Vibes: This is a boutique clone of the old grey Ross compressor, famous for its use by jam-soloing guitarists; the very popular Keeley pedal is also a Ross clone. This one has a nice added feature, a switch for three different release rates to work with different playing styles. The Ross is noted for its sustain, and this guy does indeed sustain nicely. The noise floor is a little higher than I'd like, but the swell of the noise floor as the sustained note trails off is not so obtrusive, much better than the Barber Tone Press. The attack of the compression is fairly slow, and not adjustable- because of this, strong initial spikes from your playing can peak your amp or other gear before the compression kicks in, especially at higher compression settings. If you set the release rate slow, and then play a string of notes, the peak of the first note will spike loudly and the rest of the notes will be kept under control. This may work great with a tube amp for distorted guitar, but doesn't sound so good with bass and a solid-state amp. The only work-around for this is to use the lower compression settings, so the initial output level is closer to the uncompressed instrument level. That way, there is not much peaking, and the compression is gentle and smooth. I found that setting both knobs to about 10:30 got good results. The tone of this unit is actually quite sweet, it seems to fatten up the highs and high-mids, so this is a great comp for people who solo, especially fretless, in the upper registers. The lows, unfortunately, are a tad rolled-off; not so much that you couldn't use it for bass, but it does lack oomph on the lowest notes. I would closely compare the action of this comp to the Demeter, with the Demeter having less noise, fuller lows, and cleaner attack, and the Retro-Sonic having sweeter, brighter highs and mids. The Retro-Sonic is built very well: clean-looking, petite, and solid, and the footswitch is true bypass.
Ashly SC-50: This is a neat one- it's a one-rackspace line-level mono unit from the '70s, today much prized by studio engineers for use on electric guitar. Fortunately, it also sounds great on bass. It's a unique, rather colored sound- it has a slightly hollow quality with some grit and "wooly thickness" to the tone, sort of like an old tele P bass. This tonal quality is not as strong as an "effect", but rather a subtle coloration that gives a unique, bluesy, vintage character. The high frequencies are a tiny bit muddy and muted. It's not the most transparent comp, but the noise level is very low, the low end is not rolled off at all, and the compression action is smooth, with no swell of noise on the note tail. It has a decent range of usable and good-sounding settings, and it sustains nicely. It can be set up as a hard limiter, but like many comps it doesn't do as good a job of that as I'd like- it's much better at more moderate compression. At all settings there can be a bit of a "click" artifact when the threshold is hit. I really like this one, but it won't suit players who want a modern transparent sound. For what it's worth, the one I'm testing is the "blue face" model, the first version Ashly produced, which has slightly different components than the later "black face" model. The black one is supposed to be pretty similar though. Also, the in/out switch only turns the compression on and off, your signal still passes through the gain stages of the circuit when it's "off". If you're a blues-rock player, though, you won't switch it off!
T-Rex Squeezer: Sighhhh... I had such high hopes. This is a very expensive pedal, fairly new on the market, designed for bass, from a company with a good reputation. It uses a 12AX7 tube, and it has more controls than nearly any other pedal comp, so I imagined it would be the ideal combination of fat warm sound and funky versatility, with (I hoped) low noise. Well, the reality is that it is just way too noisy. There is hiss even when the Gain knob is turned full off; and when the Gain and Volume controls are brought up to unity gain level, it sounds like a waterfall. On the plus side, it really is very versatile, with a super range of possible settings, and it also has a very full low end and a bright clear high end. Also, the tone is actually very crisp and "hi-fi" (except for the noise), and not at all the sort of fat/warm tone that people hope for from tubes. Interestingly, the noise does not increase/decrease as the compression level is adjusted. So they got part of the circuit right, for a versatile high-fidelity full-range compressor, but they seriously need to eliminate whatever part is causing all of the hiss. There's also a few things I don't like about the physical design of the pedal: (1) they have made it very difficult to access the tube; (2) the knobs are very close to the footswitch and they turn too easily, so you're likely to mess up your settings when switching it on/off; (3) it uses a 12VDC wall wart, which is just annoying; and (4) they installed a little orange LED in the base of the tube to light it up, which I think is tacky. I think if they redesigned this pedal without the tube, aiming for low noise, and chose a more logical power supply and improved the knob placement, they'd have a real winner. But that is not the case here.
dbx 1066: I spent a couple of hours directly A/B'ing the 1066 and the 166A. They have the same basic features, but the 1066 is the next tier up from the 166A, and costs twice as much. However the reality is they sound almost identical. The 1066 has attack and release controls (as opposed to the "slow/fast" switch on the 166A), as well as much more LED metering and light-up switches, so it looks both fancier and more intimidating. All that is good for dialing in the exact setting you want, but I actually found myself picking settings that sounded identical to the default attack/release settings of the 166A (in "slow mode"). So for bass, the extra controls may not be necessary or even helpful. As far as the sound quality, they are identical in the lows and mids, but the highs did sound slightly more "present" with the 1066. So in my opinion the 1066 is excellent, but there's not much point to spending the extra money compared to a 166A, unless you are picky about the high frequencies. Be sure to read my notes about the "contour" function in the 166A review. Note that with both models, higher compression ratios seemed to damp the high frequencies. The gate function is a little bit better with the 1066 because you can select the gating ratio, but it's still a bit more obtrusive than I'd like. The "PeakStopPlus" limiter, again, does nothing. I don't know if I just had bad luck and got two dbx units with broken limiters on both channels, or what, but as far as I can tell that function is worthless. However that doesn't stop the unit overall from being an excellent transparent compressor, certainly one of the cleanest and fullest-sounding ones I've tried. It's worth noting that the 1066 runs a bit hot, so you don't want to rack any temperature-sensitive items right on top of it.
Digitech Bass Squeeze: Don't bother. First, the signal has a noise gate on it which cannot be disengaged, and it sucks. It chops on and off, and sounds like someone spitting a hair off their tongue, or turning a faucet on and off randomly. If you choose notably different high and low band settings, the mids and the x-over point sound artificial and crappy. The compression amount controls are not intuitive and they don't operate like other compressors. At all higher settings the noise level is insanely bad. On the plus side, at light comp settings there is no rolloff of the highs or lows, the noise is tolerable, and the compression works well enough. If you set both High and Low bands to about 10:00, it actually sounds fairly punchy. But I would not even recommend it to somebody on a tight budget, when you can get an LMB-3 for the same price any day.
BBE Opto Stomp: This was a good surprise, for a change! I paid the same amount for this (used) as I did for the Digitech, but the BBE is so much better it's not even funny. There is barely any noise, no rolloff of the lows, and the highs are pretty good too. The compression action is smooth and natural. It doesn't even get noisy when you crank the compression up high. The only notable issue is there is a little fizzy artifact sometimes; it's very quiet, less noticeable than the "pop" artifact of the LMB-3, but it still needs to be mentioned. Also, like the Punch Factory, the compression available is fairly gentle; this pedal is not suited to major squashing or limiting. I think this pedal is meant to be a direct competitor to the Punch Factory, since they are both optical comps at the same price. I have to say, the BBE wins by a knockout. It has a better range of compression, better tone clarity at high settings, a 15dB pad switch for active basses, and the construction is superior: the jacks are mounted to the chassis (not to the board), the footswitch is true bypass, the jacks and knobs are metal instead of plastic, and the components inside are fairly high quality. Overall, I'm impressed.
Symetrix 501: This is a one-channel one-rack-space line-level unit. I had read many mentions of the 501 on pro-audio forums, where they said it was particularly good for bass. It is! Symetrix, like Ashly, does not fool around. The sound quality is pristine, with almost no noise, and no rolloff of highs or lows. The construction is rugged, the controls are simple, and there is a wide range of usable settings. It took very little time for me to find a crisp, punchy, articulate setting that sounded equally good on the highest and lowest notes. I spent some time rigorously A/B'ing it with the dbx 1066- they are equals in sound quality overall; the Symetrix sounded notably "crisper", but the dbx sounded a bit "sweeter" (possibly due to the dbx rolling off the highest frequencies). The dbx was much more complicated to set up. The peak limiter on the 501 works fairly well, although there is an occasional artifact when the threshold gets hit hard. But the compression side has no audible artifacts. This comp has a terrifically clean and sharp hi-fi sound; the only "flaw" is that it can sound kind of dry, with no magical tone fattening. Other comps may be sexier, but I would rely on this as a clean, solid workhorse with a big full-sounding low end. It's one of the few I'll actually keep. *Update: Symetrix made several versions of the 501 over many years. Most use a dbx VCA chip to control the compression, but one of them (known as the "silver toggle" version) uses a Valley People VCA. You can recognize that one by the metal toggle-style power switch; the others have a plastic pushbutton power switch. The silver toggle one is more coveted, but is it any better? I A/B compared them, and felt that the toggle one was smoother and less aggressive-sounding than the pushbutton one. The pushbutton one has a slightly "harder", more cutting action. They sound equally good in my opinion, just different.
Rane DC 24: We have another winner! This one has long been known as a favorite among bassists. It is a two-channel rack unit with an excellent crossover built in, so it can be set up as a dual-band processor. This allows it to only compress the actual frequency range that needs it, for example preventing "drop outs" of your signal when a big bass peak hits, by allowing the highs through uncompressed. Because of this it is very good for a consistently articulate sound, as well as being good for heavy hitters who need to keep a lid on it while still sounding somewhat natural. There is barely any noise at all, and no rolloff of the highs or lows, although the low end is not quite as "big sounding" as some other comps. The crossover point has no artifacts that I can hear, although different settings will affect the way the lows and highs are heard, like using an EQ; the overall tone is very transparent. The limiter function is pretty decent, and not especially prone to "pops" or other artifacts. The expander/gate is fairly hard to figure out, and that limits its usefulness. However it does work well, and at low ratio settings it sounds more natural than the gate on the dbx units. By activating the gate only on the high channel, you can gate hiss and high-pitched background sounds without impacting the lows, which is pretty cool. I wish this unit had attack/release controls instead of the expander/gate, but even so, the fixed attack and release settings happen to sound great for general bass usage. It does have a lot of knobs and switches, though, so it's not easy to set up; but the results are well worth the effort. It's easier to get a full-sounding low end from the dbx 1066, 166A, or Symetrix 501, but patient experimentation with the DC 24 will get good results. The 166A and 501 are much easier to set up, and the 501 is also more aggressive sounding. But the DC 24 has a better limiter than any of them; also its high frequencies are smoother-sounding than the 501 and brighter than the dbx units. As an experiment, playing loud low bass notes -with the low EQ boosted- into the 501 and the DC 24 really shows their differences: the 501 will clamp down hard on the whole signal, resulting in a big bassy dub tone with minimal highs; the DC 24 will clamp down only on the lows, giving a more "controlled" sounding bottom end and allowing plenty of upper frequencies and finger articulation sound to come through. Each of them sounds awesome in their own way. With a normal, less exaggerated input signal, the difference is less obvious.
Guyatone BL2: This is a bass limiter from their "Micro" series, and it's a little pedal about 2/3 the size of a Boss. It actually sounds pretty good. The tone and action are similar to the LMB-3, with good frequency range and fairly low noise, but there are a couple of audible artifacts. The can be a little pop when the threshold is hit hard, and also there can be kind of a "rustling-sounding" modulation on the bottom end when you slam it hard with a big low-frequency spike. But on the other hand, it will actually stop those spikes from getting through, which a lot of more expensive limiters don't do so successfully. It has a switch for two attack settings, both of which sound good, as well as level and threshold knobs. The threshold knob is "backwards", in that a "0" setting is the highest threshold and a "10" is the lowest. But I guess it makes sense if you think of the 0-10 as "least effect" to "most effect". The construction of this pedal is ultra cheap: plastic jacks mounted to the circuitboard, stamped sheet-metal housing, held together with a rubber ring instead of screws. The footswitch is flimsy and not true bypass. When I opened the pedal up to look at the insides, and then put it back together, it stopped working. So I opened and re-closed it up again, and it resumed working fine. In spite of that, because it is small and effective, I use it on my pedalboard right after an envelope filter that puts out a crazy volume spike, since I keep that in an fx loop with a separate footswitch anyway.
Behringer BLE100: This is Behringer's copy of the Boss LMB-3. It is a nearly identical copy in both form and function, except for three things: The housing and footswitch are made of cheap, brittle plastic; the knobs sit on thin plastic stems; and there is a significantly higher amount of hiss. If you can't afford the $50 a used LMB-3 costs, here's a $20 solution; but realize that the LMB-3 will still be working ten years from now, and the Behringer may not last ten stomps. And again, it is noisier than the Boss.
DOD FX82: This was probably a better-than-average "beginner's" comp pedal when it first came out: the construction is solid, the comp action is smooth and punchy, the highs and lows are good, and the hiss level is tolerable. But it seems to amplify background sound in a unpleasant way- with a passive bass it wasn't so noticeable, but with an active bass the background noise was shrill and annoying. The footswitch is not TBP, and the bypassed tone is actually quite poor. So, I guess if you only use passive basses, and if you leave the comp switched on all the time, this is a pretty decent-sounding pedal.
Rocktron Big Crush: Not good. First thing, the "bypassed" signal level is drastically attenuated, so it messes up the gain stages of the rest of your rig. Second, with a low-to-medium "sustain" setting it sounds weak and hollow, with bad rolloff of the lows. At a high (2:00) sustain setting the signal sounds good and strong, with much better low end, however turning up the sustain also turns up the noise level. And turning the sustain knob up past 3:00 caused the signal to cut out altogether, for no reason I can think of. The footswitch is not TBP, and it makes crackling noises if you tap your foot anywhere near the switch. Honestly, the Behringer works better than this thing. I know some fans of Rocktron gear who will be disappointed by this review, but I'm just reporting the facts as I see them. Perhaps this one was defective?
FMR RNLA: This is the newer cousin of the RNC, and is in the same 1/3 rack stereo line-level format. It is advertised as having a more "colored" tone and "gooey" compression action, and I can kind of agree with that description, although those qualities are much more subtle than you might expect based on the ad copy. The noise level is extremely low, and the highs and lows are not notably rolled off, but distortion is still a problem. At most settings there is a slight "click" of distortion on the attack, and I was only able to avoid that by setting both the attack and the release to their slowest settings, and choosing a low ratio. At fast settings the distortion is flatulent and obnoxious, like a motorboat. Also, at all settings there is a weird "crackling" static-like sound on the sustain of each note. It is completely different from the click of hitting the threshold,unrelated to that, and it sounds like a bad wiring connection. However I'm fairly sure it is not a bad connection, because I was able to increase the amount of the crackling noise by choosing a faster release time, or a higher ratio, or by switching on the "log" release setting. Also the noise goes away completely when I hit the bypass switch. This crackling sound is so totally unacceptable that I wonder if the unit I got is defective. *Update: I initially planned to ask FMR about this, send them some recordings of the distortion and crackling that I hear, and make such adjustments/mods/repairs as might be needed. But frankly I don't have time for that. I have gotten such good results from such a wide range of other compressors, that I don't want to spend all kinds of time and effort trying to figure out why I have such a hard time getting good results from this one. For what it's worth, FMR has suggested a mod for improved bass response in the RNLA, which involves replacing two capacitors. But I have not done this mod, as the components in question are SMD (miniature) and I don't have the tools or time for SMD work.
Trace Elliot SMX: This is a very cool older pedal, no longer in production. It is a dual-band comp, one of the very few out there, and it has a cult following among bassists. It's a bit over twice the width of a Boss pedal. Unusual features include: separate knobs to control the amount of compression for the high and low sides of the crossover; a "tilting" EQ knob that emphasizes either the highs or the lows; and a second footswitch to bypass only the high band of the compression (meaning only the lows would get compressed). Also, it runs on 18VDC, which means either using two batteries, or finding an 18V adapter that will fit (the "normal" Boss-type plug does not fit). The center frequency of the crossover is 350Hz, but the upper and lower bands actually overlap between 225Hz and 900Hz. The compression attack is not adjustable, but they preset a fast attack for the high band and a slow attack for the low band, which seems like a good setup. The noise level is fairly low- not the quietest, but acceptable. It does roll off a bit of both the lows and highs. The overall tone and action are quite smooth and musical, clean and punchy, at most comp settings; only at the highest settings it can sound a bit "artificial". At high ratios there can be the usual "pop" artifact when the threshold is crossed, however even at the highest settings it does not act as a limiter on the strongest peaks- the maximum ratio is 8:1. So this pedal is not up to the same audio standards and capabilities as the Rane dual-band comp, but it does sound quite good, and the differences would be less apparent while playing live on stage. Dual-band compression in general can allow much more finger-articulation sound and upper harmonics from your bass than a single-band system, so the Trace SMX is definitely a worthy contender if those qualities are important to you. The construction of the pedal is very heavy-duty; the footswitches are not TBP, but the bypassed tone is clean.
Aphex 320A Compellor: This is a two-channel rackmount unit, and it's quite different from the other comps I've reviewed. It combines compression, limiting, leveling, and gating, and those functions are all controlled in an interconnected way by an automatic "program adaptive" system. The controls on the front panel do not directly set the parameters of the compression or leveling, but rather they set up a framework around which the automatic system makes its decisions. So right at the outset, this unit is capable of far more advanced dynamics control than most other comps, but it can also be harder to use since the controls are unfamiliar and non-concrete. It doesn't generate any noise of its own, although like all compressors it can amplify existing noise at higher settings. There is no rolloff of the lows, and the highs only roll off a bit at the highest compression settings. The tone is completely transparent. The stated purpose of this processor is to normalize (match the output levels of) low-level and high-level incoming signals. So it's ideally suited to broadcast work. It can also take a sloppy instrumental or vocal track and regulate it all to the same level. I used it with two basses: a passive with fairly even output from string to string, and an active with an overpowering B string. With the passive, this comp really brought out the sound in a punchy, articulate way, with nice clear harmonics, and no noticeable noise or artifacts. With the active, the automatic levelling functions were trying so hard to regulate the signal that the noise level would jump up and down, and playing that B string hard caused a lot of distortion. Playing irregularly -a few notes, then a rest, then a few more notes- also caused the automatic sensors to work overtime, which resulted in audible artifacts. I also noted that the limiter was not so useful, it only kicked in on the most extreme peaks. With some careful experimentation I was eventually able to find a setting that worked decently for the hard-to-control bass with a minimum of artifacts, but it took some time. Whereas with the more even-output bass, with steadier playing, it was fairly easy to find a clean, natural-sounding, noiseless setting. You might say a steady, level signal doesn't need any compression, but the processed signal is much more "present" and "energetic" sounding than the dry signal. So overall my impression is that this comp is a fantastic tool, which really does offer some valuable processing power and a super clean sound; but it is not well suited for use in a bass rig where the dynamics and signal peaks can vary so wildly. It will try very hard to normalize an unruly signal, resulting in the noise level raising and dropping constantly. "Extreme" input signals can cause distortion or other artifacts. On the other hand if your technique and signal are already fairly even, and you just want to enhance the punch and harmonics, and set your place in the mix, this is an excellent tool for that purpose.
Keeley: OK, I finally got a Keeley. Among guitarists, this is probably the most positively-reviewed comp ever, but bassists have not gotten into it as much. I got the four-knob version; the regular model has attack and input trim pots on the inside, but those controls are very important for getting good response from a bass, so having those pots accessible on the outside is a very nice feature. Overall the tone of this pedal is exactly like the other Ross clone I reviewed, the Retro-Sonic. It's fairly transparent, with a bright sparkly high end, punchy mids, and good sustain, but there is some noticeable rolloff of the lows. Also there is some noise, but it's not bad; although it does seem to amplify preamp noise from my active bass more than some other comps. With a four-string bass, live on stage, the lows would be sufficient, and the hiss would not be noticed. But if you play a 5, or detune, or record with it, those issues are audible. It's not an extreme compressor, it's mostly suited to light or medium compression, although it can be pushed if you want. Just as with the other Ross, I feel it's best suited to fretless jazz players or anyone for whom shiny high-end articulation is most important. The Keeley actually has a lot more natural "action" than the Retro-Sonic, I'm not sure why. The construction quality is top-notch, and the footswitch is true bypass. The one downside to having the four knobs on top is they are easy to accidentally turn while stepping on the footswitch, but that was unavoidable with such a small sized pedal. Actually, the more I work with this pedal the more I love the fullness, brightness, and harmonic richness it adds to the mids and highs. If it weren't for the noise and low-end loss, this would be one of my favorites by far. I tried replacing the input cap with a higher value, but unfortunately that did not improve the low end at all; it only resulted in a boost to the mids and some attenuation of the highs. Replacing the output cap with a larger value may be a solution (see the Barge RC-2).
ART Levelar: This is a one-channel line-level tabletop unit, not much bigger than a pedal. It can fit in a rack space, but it would need to be attached to some sort of shelf. It is a tube comp, with the obligatory 12AX7. It can be found used at very cheap prices, but it actually sounds really good! There is a small amount of hiss, which does swell up on the tail of a sustained note, but it's no worse than most solid-state comps. The highs and lows are quite good, not the deepest or brightest, but good. The tone is a bit dark and muddy-sounding. There can be a little click on the attack, depending on the input you feed it, but the action overall is smooth. The only attack/release control is a button to switch between "auto" and "fast"; The auto setting works pretty well for bass, although I wish it had more controls. The ratio control is also limited to a button to switch between "compress" (~2:1) and "limit" (~6:1). Both settings can be useful and good-sounding, but only for moderate non-extreme compression. This tube comp doesn't have the fatness or gooeyness you might hope for from a tube device like the EHX Black Finger, but the noise level is far more acceptable. Excellent bang per buck!
Summit Audio TLA-50: This is a line-level half-rack tube comp, from a company known for high-end studio processors. It retails for around $600 USD, and the build quality really shows it- the chassis, controls, and components are all top-grade and built in a very refined and solid way. The tone is clear and articulate, with no rolloff of highs or lows, and the lows are nice and full-sounding. The compression has very useful controls- just enough to dial in the right setting, without being confusing or tricky. Here's the thing: it is noisier than I expected for a piece at this price point. I tried using a few different preamps (including their own TD-100) and various gain settings, with no real improvement. The noise isn't outrageous, but honestly the cheapo ART Levelar has lower noise. Also, while the tone and action are quite nice, there is nowhere near the "fatness" or character one might hope for from a fancy tube device. Instead it is smooth, level, and a bit boring. So it does work great, and is built to a very high standard of quality, but honestly I can get more exciting tone or lower noise from devices costing far, far less.
Alesis 3630: This rackmount two-channel unit is popular because it offers a lot of features for a very low price. I picked this one up for about $40 used. It is nicknamed the "dirty six dirty" because it is so prone to distortion, especially on bass frequencies. I'd say it earned that name, because indeed it puts out a glitchy clipping sound whenever the threshold is crossed. It is possible to find settings where it will not distort like that, but (as far as I can tell) those cleaner-sounding settings are not actually doing any useful compression or limiting. It also features a noise gate, which is like most cheap gates- useful if your signal is desperately noisy, but terrible otherwise. I would not engage the gate unless I absolutely had to. The frequency range of this unit is pretty good, with no notable loss of lows, and only a bit of rolloff of the highs. But the tone is sterile and weak. Many people have modded the guts of their 3630, and claim to have gotten much better tone and performance from it. Even so, I would only bother with that if you already have a 3630 and want to monkey with it. If you just want to save money, get a used Ashly or Symetrix unit instead, sometimes they go for pretty cheap.
Empirical Labs Distressor EL8-X: This is an incredible piece of gear. It is a rackmount mono line-level unit designed to emulate many classic coveted vintage studio comps. I haven't used the high-end vintage pieces myself to compare, but I can clearly hear a distinct variety of chunky old-school sounds and compression actions at the various recommended settings of this unit. It is also capable of an endless range of its own unique settings, from smooth to punchy, from soft to balls-out aggressive. In addition to providing all those styles of compression, it is designed to provide modulation (subtle and not-so-subtle distortion) ranging from a "warm fatness", to a saturated-tape clipping, to a furry old 18" speaker tone, to an outright gritty overdrive. The distorted qualities can also be switched off for clean tone. All of the tones and compression actions have a funky, edgy quality. It can also be set at a 1:1 ratio so you can apply the EL8's tonal qualities to your signal without compression. There is no inherent loss of highs or lows, except at settings which emulate devices that would have had some rolloff (to be clear, that does mean there can be some high or low rolloff on some settings). There are no unwanted artifacts even at the highest settings. However it should be noted that this unit was designed to have "musical" desirable artifacts and coloration, so the tone is not always transparent- it's not supposed to be. Also, it can have a bit of noise, although I'd bet it is far less noisy than the older devices it is modeled after. The "X" version of the EL8 has two additional features: a setting to improve the stereo spread when using two of them, and a switch which emulates pushing in all four "mode" buttons on an 1176. Those two features are neat, but so far I don't think they are all that useful for bass. It's an expensive piece (up to $1500 USD)- is it worth it? I'd say it is beyond overkill for almost any live gig, where most of the tonal subtlety would be lost anyway, and some of the saturated tones might sound muddy through a PA. The aggressively noticeable sound of it may not be something you'd want to use all the time. And if all you want is clean transparent compression, the Rane or Symetrix comps will do just as good of a job (maybe better) for a tenth of the price. But if you are in the recording studio, and you want a broad spectrum of punchy vintage tones, there is almost nothing else on the market that can do everything this Pandora's box of compression effects is capable of. Plus it is far more reliable, consistent, and versatile than the older gear it claims to emulate. And for certain purposes, it sounds freaking awesome!
Furman LC-3: This is a mono rackmount unit from the mid '80s, able to work at either line or instrument level (as long as your instrument has a fairly hot output). It has a nice warm full tone, with no rolloff of highs or lows. It is a bit noisy though, especially on the swell of sustain on the tail of your note. It also is very prone to a crackly sort of distortion, which can only be minimized by setting the release to maximum, as well as a clipping on the attack which can only be minimized by choosing a slow attack. All in all, the Furman reminds me very much of the RNLA! It even has similar-looking red knobs. I upgraded all of the opamps in this one, which did seem to improve the noise level a bit, but not enough, and it did not help with the clipping. The tone is so fat, and the knobs so cool-looking, that I want to like this unit... but its flaws are too obnoxious.
PreSonus Comp16: This is a 1/3 rack-width line level mono unit which is essentially an update of their old BlueMax. It features sixteen presets which are not user-adjustable. Of those, only one is meant for bass guitar, and it actually sounds quite good. Nice big lows, bright clear highs, very low noise, minimal artifacts. It's about a 3:1 ratio, for a very gentle compression. All of the other settings were useless for bass, as they distorted in a buzzy unpleasant way. Some of the settings only buzzed or clicked a little, but some of them sounded like a bumblebee. So compared to the BlueMax, the Comp16 has much better highs and much lower noise, but it has only one non-adjustable "good" setting for bass, while the BlueMax had a lot more versatility. The Comp16 has an illuminated VU meter, which looks really cool but is functionally useless. If you happen to like the one good bass compression setting this thing has, or just want a rackable unit that's as simple-to-use as possible, this is a fine choice. *Update: the preset-selection knob on this one has just started failing for no apparent reason.
Alesis NanoCompressor: Another 1/3 rack, but this one is much older and can operate in stereo. Also it has no presets, but instead has a good versatile range of controls, and useful metering. The sound is almost identical to the Boss LMB-3: clean, dry, with fairly good highs and lows; but prone to a "pop" artifact when the threshold is crossed. The noise level is not as low as the PreSonus, but it's pretty decent. Strangely for a rack unit, this seems to work a lot better at instrument level (feeding into a preamp) than at line level. The output is very low, even when the compression is bypassed. So even though it's rackable, I would put it on a pedalboard instead; it's pretty small anyway. Think of it as an LMB-3 with more controls and versatility, but no footswitch.
Aphex 661: Among the higher-end Aphex rack comps, the 661 (or its earlier version the 651) is the one you want for a bass rig. It's a mono line-level unit with a really nice set of features. It allows for either automatic ("Easyrider") compression control or a good set of manual controls; the Easyrider setting sounds/acts very smooth like an optical comp, and the manual settings allow a more dramatic range of control. There is an enhancer/maximizer function labeled "SPR" which really does bring out a tighter and more energetic tone; I wouldn't use it all the time, but it sounds really great for certain applications. The "Tubessence" tube/valve circuit, using a single 12AT7, is a pretty subtle thing- the overall tone is clear, warm, and natural, but not exaggeratedly "tubey". Another nice feature is the high frequency expansion. In order to counteract the loss of highs associated with strong compression, this circuit dynamically un-compresses an adjustable range of high frequencies in proportion to the amount of overall compression applied. It's subtle, but very nice sounding on fingerstyle playing. Overall, this comp has no rolloff of highs or lows, almost no artifacts, and the noise level is very low. It's a fantastic unit, one of the best and most useful I've tried. I do have some criticisms of it: it's deeper front-to-back and heavier than many other rack comps, and it runs very hot. Also, while the special features are quite good, they are honestly much more subtle than the ad copy would suggest. For many players, the features might be more than they need, but for the finicky user this one is a really nice choice. Because it runs so hot it might not be a great choice for a gigging rack; otherwise, the 661 sounds better (to me) for clean/natural sound than any other comp I've tried. These units are a bit expensive new, but you can find much more reasonable prices for used ones. Just be careful though, because it seems like the majority of those Aphex bargains on Ebay were pulled from bar/club PA's where they've been abused, and are sold "untested, as is" with no warranty. Don't fall for that BS; only buy one where the seller asserts it has been tested and works without any issues.
Valley People Dyna-Mite: This is a vintage line-level rack unit, which was available in several different versions. The one I'm testing is one of their early versions, a single-channel unit with silver aluminum trim framing the face. It is primarily a limiter, with an infinity:1 ratio, but it can also be set up for distinct functions such as expansion, gating, or de-essing. As a limiter, the Dyna-Mite is insanely punchy. After an hour or two of testing, I felt like my ears had been pummeled. This is not a compressor you'd use for all purposes, but if you want an extremely aggressive punch, this one delivers. It has just a bit of noise, but not bad- actually about the same as the Distressor. The lows are big and full, and the highs are not rolled off notably; the overall tone is a bit dark, but very fat and "in your face". The controls on this one are not all intuitive or the same as you'd find on other compressors, so it is worth your time to find a copy of the manual. The Dyna-Mite is not a versatile or "natural" compressor, but for what it does well, nothing else even comes close.
Danelectro Surf & Turf: This pedal is cheap in every way. Cheap like Behringer. The knobs seriously look like they came from a little kid's toy. It has one redeeming quality: there is almost no rolloff of highs or lows. But the compression action is mediocre and the noise level is a bit too high. There's no reason to ever buy one of these- just save up a few dollars more for one of the other cheap ones I do recommend instead.
Orange Squeezer clones: The Dan Armstrong Orange Squeezer is a classic vintage compressor which has a cult following among guitarists. There are many, many modern OS clones out there, such as the Analogman Juicer or Pedal Doctor Tangerine Squeeze; and a few interesting variations on it such as the Toadworks Mr. Squishy. The OS is so popular to clone because it's a very simple circuit, and it has a distinct compression action and tone which are different from most other compressors. It can add an emphasis to the leading edge of the attack of your notes, quickly followed by a reduction of the signal level, which rises back up in a "blooming" swell of sustain. I describe the action as a "dip and swell". The original OS only had an internal "level" trim pot, but it is also possible to get a wide range of compression action, from subtle to extremely squishy, by adjusting the bias of the transistors. For this reason, some modern OS clones include a "bias" knob; I highly recommend this feature, as it allows you to get more variety from this effect, although some builders prefer to find the one "best" setting and fix it there. The OS also tends to brighten the high frequencies just a bit, and sometimes adds a bit of very light distortion. Because the circuit is so simple, some cloners try to improve it by developing or adding onto different parts of the circuit. In my personal opinion this is a mistake, because the best qualities of the OS, to my ears, are only found in the original circuit. The only exception I would make, aside from the external bias pot, is that the original OS design does roll off some of the low end, and there are some relatively simple mods which can be done to the OS to allow better bass frequencies. Check out tonepad.com for more info about those mods. Unfortunately even after modding for bass, an OS will never have a deep, fat low end like the Demeter, and may roll off some of the lowest frequencies on a low B string. Some of the cloners who have "improved" the design seem to have tried to engineer out its unique qualities and instead emphasized the more boring, "normal" smooth/clear compression it is capable of. In my opinion, if you want "normal, nice compression", get something else, get a Demeter or a Keeley or a transparent rack unit. Get an OS instead for its unique and eccentric qualities. Also, for those of you handy with a soldering iron, a simple OS kit and plans are available from generalguitargadgets.com to build your own fairly cheaply. Note that different component choices can really change the sound quality of this circuit, so be sure to experiment with different types of caps, diodes, and IC's.
Pedal Doctor Tangerine Squeeze: This OS clone is a fairly simple take on the original circuit with modern components and features such as true bypass, DC jack, LED, etc. It has a crisp bright musical tone and a funky compression action, with plenty of percussion to the attack. It has decently low noise, but as with most OS circuits, it does lose a bit of the low end. I modded it for bass, which was a successful improvement, but it still rolls off a bit of the lowest frequencies on a low B string. The tone is not quite as "fat" as some other OS clones I've tried, but it is a little more crisp or clean sounding.
Tone Factor Pulp Mill: This one is a different approach to the OS circuit, as its "comp" knob is not a bias control, but rather a wet/dry blend. So unless you open up the housing and fiddle around with the trimpots in there, it will be at a bias setting which is on the smoother side rather than the funkier side. It has low noise, and blending your clean bass signal in allows it to have slightly better low end than the Pedal Doctor one, but it will still benefit from a bass mod. The tone is slightly darker than the PD. All in all this one seems designed so you can add just a bit of the OS flavor to your signal, rather than being a "squash box" like the PD and VTP versions. But it works well and sounds nice, if a bit subtle for my tastes. It has the usual modern touches like TBP footswitch and nice components, but the paint job on the box is a bit sloppy.
BBE Orange Squash: They originally named it the "Main Squeeze", but Digitech owns that name, so BBE had to change it. I had high hopes for this one since they did such a good bang-per-buck job with the Opto Stomp, but unfortunately they didn't do as well with their OS clone. It has a little less brightness or clarity than the PD or TF versions, and a little less "funkiness" in the action compared to any of them. The circuit has about three times as many components as a normal OS, for what reason I don't know;. The BBE is not bad, but there are better OS options out there for around the same price. It does have very solid construction and TBP footswitch. Also, it is about as good with bass frequencies as an OS can be, so it doesn't need modding.
Vintage Tone Project Citrus Squeeze: This OS clone is, of all the ones I've tried, the closest in design to the original Dan Armstrong circuit. VTP went to great lengths to use uncommon vintage components throughout the audio path, even using a carbon-comp resistor at one point. This OS has a furry warm vibe that I just don't hear from the others, with soft subtle distortion almost like a tube amp. It really is a "vintage tone". The external bias pot allows a huge range of usable and unusable settings, including some outright buzzy/gritty distortion at one point, and creamy smoothness at another. Of all the OS clones, this one is the most like an "effect". The tradeoff of the warm fuzziness is that it's not as crisp and bright as the Pedal Doctor version. VTP worked with Dan Armstrong for the last couple years of his life, and replaced this model with the "Orange Crusher", with a couple of improvements from Dan, and the bias pot on the inside instead of out. The footswitch is true bypass. VTP gave me some great customer service when repairing this pedal a few years back, but unfortunately they are no longer making any version of this pedal.
Safe Sound P1: This is a half-rack-sized compressor and preamp. It is able to run as a line-level processor, or it can take direct input from any instrument; the output is always line-level though. It is a "boutique" piece from the UK, costing around $700 USD. As with the Summit TLA-50, it is built to a very high standard of quality; however the Safe Sound delivers more bang per buck than the Summit in my opinion. It has barely any noise (it's one of the quietest compressors I've heard), the compression and tone are completely transparent, and the built-in preamp means you can use this unit as a direct connection between your bass and a power amp or mixing desk. The preamp is clean and powerful, and very "neutral" in tone. It also features an expander/gate and a peak limiter; they are handy, but they are nowhere near as nice as the other features. The limiter in particular has the same little "click" artifact as most other limiters, but a little better than average. Aside from that, my only complaint about this piece is that it may sound too clean or even "sterile" for some tastes and purposes. And again, it isn't cheap. But if you are looking for something absolutely smooth, high-fidelity, noiseless, and small, this is the unit for you. Plus, if you add a nice 1/2 rack EQ unit, it would make a fantastic channel strip pre for a clean-sounding hi-fi bass rig.
Behringer MDX1600: I have to be honest and say this two-channel rack unit was a lot better than I expected. The sound quality is very clear and fairly low noise, there is no rolloff of highs or lows, and the compression action is pretty decent and versatile. Even the limiter, though not super effective, has no pop/click artifacts that I noticed. The only thing really bad about this unit is the expander/gate, which chatters like a chilly skeleton. The "Dynamic Enhancer" function is actually a really good feature, essentially copied from the Aphex Expressor's HFX function. It dynamically un-compresses high frequencies in proportion to the overall compression, which allows a brighter, more articulate sound. Generally speaking the biggest complaint about Behringer gear is the construction quality, how it tends to break easily. I looked inside this unit, and it is not nearly as badly-made as the BLE100. However all of the pots, jacks, switches, and heatsinks attach rigidly to both the circuitboards and the housing, which means that stress to any part of the housing could cause damage to several points on the circuitboards. As long as you don't drop it, it will work as well -and sound as good- as comps that cost a lot more. For what it's worth, I have seen claims that the older non-"Pro" Behringer comps were actually built better than the current "Pro" models.
JBL/Urei 7110: Urei is famous for their 1176LN and other "vintage" compressors; for a while in the 1980's, the brand was owned and manufactured by JBL. The JBL 7110, a mono line-level rack unit, is identical to the Urei LA10; there were also stereo versions, the LA12 and 7112. This is a fantastic comp for bass, with a big full low end, a smooth warm sound, and low noise. It has one unique feature, a knob to pan between two different modes of compression: peak and average. It's hard to put into words how this works or sounds, but different settings can act/sound more like an optical comp, or more like a VCA comp, and there can be a subtle EQ-like effect as certain frequencies are compressed differently as you pan between the two modes. Unfortunately, setting the knob to 2:00 or higher (towards the peak mode) results in a lot of buzzy clipping on a strong bass signal; but that still leaves enough knob-turn to work with for audible variety. The action is capable of being very punchy or very smooth. A/B compared to a Symetrix 501, the 7110 was darker, with strong warm/thick mids, but the highs seem a bit "choked"; the 501 was more transparent in the highs, and a bit more boomy in the lows. The 661 is more even-sounding from the lows to the highs (compared to both the others), which makes it seem to have a wider frequency range with no "humps". The 7110 can match one or two tones/actions of the Distressor; so it's not nearly like an 1176 or LA3A for studio purposes, but it is a good rugged gig-ready way to cop a bit of those flavors enough for a live rig. For those of you into modding gear, the 7110 was designed to be upgradable with a Jensen output transformer, for the tonal qualities it can add. It is a very simple and easy mod, you just have to track down the correct model and size of transformer.
ART SC2: Two channel line-level rack unit. As far I can determine it is identical to the CS2. It has no low-end rolloff, but the highs are a tad muted. The noise level is higher than I'd like, but not terrible. The compression is adequate, with only minor artifacts, and the tone is neutral. The gate chops hard, but at least it doesn't chatter. These sell for super cheap. I would say this one is better for bass than the Alesis 3630, but not as good as the Behringer MDX1600.
Ashdown Dual-Band: The features of this pedal have a strong resemblance to the Trace Elliot SMX. That's not too surprising, since one or two former TE engineers went to work for Ashdown around the time this pedal was developed. Initial reviews of the Ashdown version were not so good because it only worked with low-output passive basses -anything with hotter output would cause the Ashdown to distort. However, they later redesigned this pedal so the newer ones are compatible with active basses. It is able to sound quite good actually, but only at certain settings. The controls include separate compression amounts for the low and high bands, and a tilting EQ to either cut highs and boost lows, or vice versa. But in my opinion it only sounds good if the two bands are set to the same compression amount, and the EQ is set flat; so I wish they had left the extra controls off and used a smaller chassis. The compression level controls are confusing because turning one of them counterclockwise seems to roll off the signal of that frequency range, instead of just reducing the amount of compression. So they seem to be actually "boost" gain controls, increasing the level of your signal into a fixed threshold as you turn the knobs clockwise. The Punch Factory works the same way. I don't like it, it's counterintuitive and liable to confuse anyone who is just starting out with compression. The EQ knob is pretty intense- very small adjustments yield lots of EQ change, and the only time it sounded good to me was either flat, or with a very slight tilt to the bass side. I wish it had a center detent, or could be bypassed. Another gripe is the VU meter: it "works", but it is inaccurate and mostly just decorative. But I said this pedal could sound quite good, right? Yep. Set both bands of compression to 2:00 or higher and the EQ knob at 12:00, and the tone is clear and full, with fairly low noise and very little rolloff of highs or lows. In fact it sounds big and fat in the low-mids. Setting both bands to max compression is a very strong modern sound (perhaps a bit artificial), and the max setting is actually not a very high ratio; I'd bet it's 8:1 like the Trace SMX. The fixed attack time is kind of slow, at least on the low band, so if you play slap, a lot of your spiky hits will still get through and clip your amp. This pedal is better suited to light/moderate compression. The footswitch is TBP.
FX Engineering RAF Mirage: This is a boutique handmade pedal that resembles many others in some ways: small MXR-sized box, two knobs "Comp" and "Level"; and yet it does not seem to be a clone of the usual varieties. It has an amazingly transparent tone, with fairly low noise and no rolloff of highs or lows. I A/B/C'd it with the Demeter and my favorite OS clone (by Pedal Doctor), and they were all equal in quality, but different in flavor. The Demeter's tone seems more "solid" or "focused" than the dry uneffected signal; whereas the Mirage essentially left the original dry tone unchanged. The OS was brighter and more percussive than the other two, but not as beefy in the low end. The Mirage has the most "open" and un-effected sound. It seems to have a fixed ratio of 3:1 or thereabouts, a pretty low ratio, so it is best suited to light smoothing and bringing out harmonics, rather than peak limiting. The "Comp" knob appears to adjust the threshold. The Level knob is at unity gain at around 9:00, and this pedal can provide an insane amount of clean boost. I actually think this pedal was designed for use with a tube guitar amp, to push it into overdrive while also providing moderate compression. It would be equally great for any bassist looking for a boost during their solos, or wanting to drive their amp into stoner doom OD. In my opinion, if it weren't for the clean boost potential, this pedal would honestly be competing more with the Punch Factory or Opto Stomp than with the higher end of pedals, just because of the limited range of compression ratio. However it does sound really nice, not altering or hindering your instrument's tone at all, and it is smaller and cooler-looking than the Punch Factory or Opto Stomp. It has two LED lights: one for on/off, and the other lights up brighter as the compression increases. The construction quality is solid, and the footswitch is TBP.
Jacques Fat Burner: Fat is right! This is compression as an "effect", not as a subtle or transparent gain control. It is a squasher, a sustainer, and a thickener. It reminds me of the Boss CS3, except with fatter tone, more versatility, and much better low end. Like the CS3, it can also be pretty hissy at all but the lightest settings. But most other compressors would be equally noisy at this level of serious squash. Tonally, it can be a bit furry or even muddy, but the lows and highs are not notably rolled off. The "Muscle" knob adjusts the sound from smooth to biting; I suspect turning it to the left speeds the attack and softens the knee, while turning to the right slows the attack and hardens the knee. I like it at 12:00, but there are good sounds at all the settings. The Fat Burner also includes a decent headphone amp for practice, which doubles as a +10dB output to overdrive your tube amp if you like that sort of thing. The construction is a mixed story: the housing is sturdy cast metal, but the footswitch is cheap-feeling plastic. The pedal is smaller than it looks in the pictures, it's actually a little smaller than a typical Boss or Ibanez pedal. As far as I can tell, the bypass is electronic, not mechanical/hardwire, so it is debatable whether it is "true bypass" as they claim; however it is an excellent clean bypass either way. If you were considering an EHX Black Finger or similar pedal for "effect" compression, I think the Fat Burner provides equally fat squash in a much smaller package, with somewhat better noise levels. It's also perfect for the Tony Levin sound. I like it.
Tech 21 Bass Compactor: You know it's bad when "noise suppression is included for your convenience". This comp can be extremely noisy, and the noise gate function is jittery and jumpy. So if you play with any space at all between your notes, you'll hear a battle between feedback-y noise and the gate trying repeatedly to clamp down. It's kind of a cool lo-fi effect, but it sucks otherwise. This issue is not so noticeable if you turn the Comp knob down to a minimal setting, but then it isn't compressing much either. The tone and frequency range are actually quite good, if you can get past the other issues, but not good enough to be worth the hassle. The footswitch is not TBP.
Carvin CG200: A rackmount two-channel optical comp with gate. I had high hopes- partly because I like Carvin amps, and their instruments and cabs are known to provide a lot of bang per buck; and also because in theory this unit "should be" something like the Demeter, but with a lot more control over the parameters. Unfortunately, Carvin dropped the ball this time. The tone is decent but a little bit "choked" sounding. The compression action is jerky, not smooth. The gate is much choppier than I'd expect considering it has ratio and release controls. And it took me a long time to dial in good settings for compression. I enjoy tweaking controls and fine-tuning, but honestly I got frustrated hunting for the good sounds from this unit. On the positive side, it has very low noise! The bypass switch does not actually remove your signal from the processor, it just turns off the compression; so it is very difficult to A/B your compressed and dry sounds. And if you're using one channel, the LED's for the other channel also light up in response to the incoming signal. Who knows why. The construction quality is below average; in fact, the interior design/layout is nearly identical to the Behringer rack unit I had. They cut corners wherever possible. The knobs and switches feel cheap, and the labeling on the front and back are just vinyl stickers, which were not applied very well. All in all, yes it is possible to get decent usable sounds and functions from this unit, but no I don't think it's a good investment.
EHX Soul Preacher: This is from their new "Nano" series of reissues, where EHX takes their classic older pedals and redesigns them into tiny boxes using micro components. As with just about all EHX effects, the Soul Preacher is a love/hate thing. On the positive side, it has fantastic tone, with fat lows and crisp highs, and the action is very percussive and punchy. But unfortunately it is hideously noisy. Even beyond the usual line-noise amplification of all compressors, it generates its own white noise. And the compression it offers is so extreme that I only found it usable with the "Sustain" knob turned all the way to the lowest setting. Any of the other settings would be cool as an unusual effect, except the noise at those compression levels is not tolerable. I tried it with both active and passive basses, and got the same results. There is a trim pot inside to adjust input gain; it can help a bit. The footswitch is TBP.
Barge Concepts RC-2: This is another Ross clone. However, this version has an internal switch which selects a larger output capacitor for better bass, and it sounds really good. The RC-2 has the same smoothness, sustain, and warmth as other quality Ross clones, but the fact that it can also put out a lot of fat, full low end puts it way above the Keeley and others in terms of bass usability. Unfortunately, just as I found when trying to mod the Keeley in a similar way, beefing up the bass means losing the bright highs that the Rosses are famous for. The highs are not completely cut off, but the upper end does sound a bit muffled or damped to me, especially in comparison to the mids, which seem to get a slight boost. However the tone overall is warm and natural, and the action is very smooth. It reacts well to a wide range of playing styles, and handles a loud low B. This is the best Ross clone I've tried for bass, and it is a strong contender against the Demeter and EBS for top ranking. It's not noise-free, but the noise is "normal" and not bad at all; and the voicing may be wrong for some people's tastes, but just right for others. I'm adding it to my list of recommended pedals! The footswitch is TBP. Also note that their newer model, the RC-3, is the same circuit in a smaller box.
EMMA Transmorgrifier: This pedal has a very hi-fi quality to it, with a flat, tight, uncolored sound. It really tightens up the incoming tone. It has a bright clear high end, really crisp and airy; unfortunately it does seem to lose a bit of the lows, and is not fat or full on the bottom. It's not bad though. There is more noise than I would like, but not so much that I wouldn't use it. For comparison, it is a bit noisier than a modded Boss CS3 at seemingly equivalent compression settings. But like the CS3, it has a strong ratio even at low settings, so it will clamp down on hard incoming spikes, making it a good choice for slappers or anyone else who needs peak limiting with a bright crisp clean sound. Note that the recommended settings in the instructions that come with the EMMA are insanely heavy squashing settings only suitable for lead guitar type effects. A realistic ratio knob setting for bass is around 9:00 or 10:00, anything higher is all noise and squash. The attack and release controls are fully useful across their range though, and they are a good feature to have. The footswitch is not TBP, but the bypass is clear sounding.
ADK CLA-1: This is another semi-high-end half-rack unit in the vein of the Summit TLA-50 and Safesound P1. It is an opto design more or less based on the Urei LA3A, aiming for an old-school "character" compression with the added feature that you can swap in different opamp modules for different tonal qualities. At first I was a little disappointed by this unit because the front panel controls are minimal and poorly marked (there are no numbers indicating dB, ratio, mSec, anything), and it seemed a bit noisy. But the more I worked with it, the more I have fallen for its fantastic tone and action. You have to learn its quirks, and you have to set it "by ear" rather than by principle, so it is not for beginners. But once you have dived in and spent some time learning how to work with it, the tonal results can be awesome- lively, punchy, "3D", funky, warm, syrupy, and surprisingly articulate. There is no loss of highs or lows. Even in spite of its quirks and slightly elevated noise floor, I keep reaching over to switch it on, because it just makes everything sound so good. The noise level is about the same as with the Summit TLA-50, but the ADK's compression is far more "interesting". At this point I have only used the stock ADK opamp (their "DOPA-1") and an API 2520; the API has a slightly lower noise floor and a slightly darker sound. I also bought a John Hardy 990C, but for some reason it is not working in this unit. I have tried to get answers from ADK, but they are a bit spacey. When I called to ask questions about the CLA, the main guy there told me he had no idea how it worked, his design team came up with it, and he didn't even know what information was or wasn't in the owner's manual (and incidentally the manual says almost nothing useful). I'm still trying to resolve the issue with the Hardy opamp, and I have to admit it's frustrating... but again, this compressor just sounds so good that I can't be too mad about the other bumps in the road. It has a switchable "bass pass" function where the compression is only triggered by frequencies above 150 Hz, which keeps the highs from being "swallowed" by the more intense compression that would normally result from peaks in the stronger low frequencies. They advertise this as being especially good for bass instruments but it seems to me that for bass, spikes in the lows need limiting more than the highs, so I haven't been using that feature; however it could be useful in some appplications. The external appearance of this unit is a bit lame when you consider the high price point, but the interior construction, layout, and components are excellent. The VU meter actually seems honest, for a needle-type meter, and it has the neat feature that the light in the meter dims when the unit is bypassed. The bypass is TBP. I really like this unit, it has become one of my favorites for its "tone magic".
Boss CS-1: This is one of Boss's earliest comp pedals, and it uses a very different circuit than the later CS-2 or CS-3. It is an ultra squisher, with heavy compression at even the lowest "sustain" knob setting. Turning the sustain knob up results in a very pronounced "dip and swell" of amplitude. It's a very cool effect, but not something most bassists would use all that often. It does increase sustain, but there is a noise penalty at higher settings. At low settings the noise is not bad at all. At those settings the output level is a bit lower than unity, which is annoying if you switch it on and off; but if you leave it on all the time it's not a problem. At the more "usable" low sustain settings, I have to set the level knob to maximum in order to approach unity gain. The tone has a sort of constricted or congested sound. There is a slight loss of highs and lows; the lows are the same as the modded CS-3, but the CS-3 has better highs and a more open, natural sound. I don't mean to say the CS-1 tone is bad though, in fact it's warm and funky and smooth; but it is not the natural sound of your instrument. In short, between the tone and the action, this is an excellent comp for use as an effect, but it is not suitable for somebody who wants transparency. The footswitch is not TBP, but the bypass is pretty clean. Also, I found I was able to improve the lows a bit more by changing the resistor and cap values connected to the "normal" side of the normal/bright switch.
Analogman Bi-Comprossor: This pedal is one of the most coveted "boutique" pedal comps. It is a combination of a Ross clone and an Orange Squeezer clone, which can be used one-at-a-time or both in series. The Ross side sounds almost identical to the Keeley- meaning killer mids and highs, and a little bit of loss of low end. The Bi-Comp's lows might be just a touch better than the Keeley, as the signal is very strong just above the roll-off point; meaning the lows that it does put out are loud and clear. Again, excellent for a 4-string player, or even a 5'er under certain stage/tone circumstances. The noise level is identical to the Keeley, which is to say "not bad" but not silent either. The Orange Squeezer (AKA Juicer) side is a love/hate thing. On the one hand, the tone is one of the fattest, richest OS clone tones I've heard, really nice. And the action is excellent. On the other hand, the noise level is intolerable. I tried adjusting the internal bias trim pot, and it did what it normally does in terms of adjusting the compression response of the circuit, but it did not reduce the noise at any useful setting. The highs are excellent and clear; the lows are typical of an OS clone, similar to a Ross: good enough for some players in some circumstances, and nicely fat, but the lowest frequencies are rolled off enough to bother a 5-string player in the studio. The footswitches are TBP, and the pedal seems well-built. I'd recommend buying Analogman's Ross and OS units separately rather than in this combined version, unless you're willing to live with the noise of the OS side.
Retrospec Squeeze Box: A fairly hard-to-find discontinued unit, designed to be essentially a clone of the Urei LA2A in a pedal format. It uses two 12AT7's or 12AU7's. It actually brings your signal up to line level before the compression stage, and then the output signal can be left at line level or reduced to instrument level as needed for your application. It also has a mic-level DI out, so the Squeeze Box can be used as a front end into any recording channel or FOH while also running into an amp head or directly driving a power amp. The tone and action of this unit are legendary; one person described it very well as sounding like "being hit over the head with a heavy rubber mallet". It is punchy, fat, warm, and really nails the classic Jamerson-type recorded tone. The sound is simply fantastic. There is one down side, however: like most other tube comps, it can be susceptible to electromagnetic interference, so it will be a bit noisy in certain rooms. However in my work room it is less noisy than the EHX Black Finger. Aside from the potential noise issue, I feel the tone, action, and build quality of the Squeeze Box are far superior to the EHX. The sound is just classic vintage thump. There is a tone knob which can either roll off the highs or enhance them notably to counter the tendency of heavy compression to "swallow" the highs. Luckily, turning up the highs with the tone knob does not raise the noise level. It's fairly large for a pedal, and has a built-in AC cord; it can run at either 120 or 220 volts. The footswitch is not TBP; I believe the bypass just switches off the compression circuit, so your signal is still running through the other tube gain stages. That means it sounds very good when bypassed, but not transparent.
MXR Dynacomp: Basically the same general circuit as the Ross, and therefore similar to the Keeley and other clones. Aside from some variation in component values, the main difference is in the quality of the components and the construction. So the tone of the Dynacomp is quite good, almost as good as the boutique clones, but it is a little noisier. It sounds good for the price though, with especially nice highs; the only real problem for bassists being that like other Ross-related circuits, it loses a bit of the lows. It is not true bypass, but the bypassed tone is decent.
Maxon CP101: This pedal has a fairly transparent sound, mostly uncolored and open. The action is quite natural as well, but better for general smoothing-out of your signal than for punchiness. The highs are good, although not as bright as the Dynacomp; the lows are decent, better than the Dynacomp at some settings, but I found that the lows would seem to roll off more if I didn't have the input level and output gain set just right. Additionally, a bass with a hot output signal will cause the CP101 to distort badly. The noise level is about the same as the Dynacomp, slightly higher than some boutique pedals but not at all bad. Once you've dialed in the ideal input and output levels, this is a pretty good unit; but it took me a surprising amount of tweaking to find those ideal settings, and it worked best with a passive bass that has moderate output levels. The footswitch is not TBP, but the bypass is clean.
Boss CL-50 Pro: Boss let me down with this one. Their old "Pro" series half-rack units are usually pretty good, and I do like some qualities of their pedal comps, but this one is worthless for bass. It has a lifeless tone, average noise, and more importantly it distorts very easily and unpleasantly. It sounds exactly like the Alesis 3630, and I'd bet the circuit design for both is very similar. Also, the bypass is terrible, with a significant drop in signal level.
Alesis Micro Limiter: This is an older 1/3 rack width unit. It can run stereo or mono, and it works at either instrument level or line level. It seems to have a slightly better signal-to-noise ratio when used at instrument level. It is actually one of the more effective limiters I've used: it honestly blocks major spikes from getting through, the attack speed is "just right" for unobtrusive but effective action, the tone is neutral, and there are no notable artifacts when the limiting kicks in. The downside is it has a similar noise level to most halfway decent pedal compressors, meaning the noise isn't bad, but it is not silent either. The lows are big and full, and the highs are decent- not exactly rolled off, but they do sound slightly congested. Expect this one to do its job without imparting any "magic" to the tone, it's a great limiter but not a fattener or a "character" effect. Also worth noting that it uses a 9V AC wall wart; many of the ones I've seen on Ebay were missing the power supply, and the seller always says "any common 9V adapter will do." Not true, it needs AC not DC. The bypass sounds kind of poor unfortunately, but since it's not a stompbox you probably won't be using the bypass so much. Considering these units work so well, yet sell for very cheap, they get a big thumbs-up from me!
Joemeek MC2: Over the years Joemeek has released many variations on the same circuit idea with different letter/number names. This one is a stereo half-rack unit, updated recently from a previous model also called the MC2. It is really quite likable! It can achieve a certain amount of clarity, but most of its range of tone and action is in the more "heavy squash" and "effect" category. The tone is smooth and warm, with no rolloff of highs or lows, although the sound becomes notably colored (non-transparent) during the squash. If you hit with a very hot signal the low end can get a bit "choked" sounding. The noise level is better than average, but not silent. Comparing the MC2 directly to an ADK CLA-1 (another half-rack optical unit), the ADK sounded beefier and fatter, but the MC2 had a zingier-sounding attack and lower noise. Also the MC2 has a complete range of controls over the parameters, so it is possible to dial in different action for different signals, while the ADK has almost no parameter controls- you either like the action or you don't. The compression of the MC2 seems to kick in very dramatically even at lighter ratio settings- hit the threshold, and bam! You get squashed for a few mSec until it releases. It's a very cool effect, a lot like the "dip and swell" of the Orange Squeezer, and I could see many bassists really enjoying the funky swing it provides. However people looking for the most "natural" and transparent action should probably look elsewhere. The gain reduction meter is also too exaggerated, it doesn't seem to match reality. Hitting the MC2 with a hot input signal, it will not act as a hard limiter- some spikes will get through. You can reduce that by choosing a very fast attack, but I felt the tone and action suffered at those settings, sounding more flat or artificial. I got the best results for my tastes with a slower attack setting and figerstyle playing. The bypass is pretty decent. If you like funky compression and don't mind spending some time dialing in settings, this is a very good unit!
Aphex 720: The "Dominator II" is a three-band limiter, meaning it divides your signal into three frequency ranges and applies limiting individually to each range, then mixes the three bands back down to one. It's a line-level rack unit which can operate in mono or stereo. It seems like it should be ideal for a bass rig, since many bassists don't want a lot of compression, they just want the bigger spikes leveled; and multi-band processing is typically more transparent, as only the offending frequencies get reduced. However the reality is this unit doesn't sound good. It is an effective limiter, but it distorts badly whenever you cross the threshold. Further, the lows are rolled off, and the tone overall just sucks. It's like the low mids are gutted and castrated. After a few hours of tweaking knobs, I was able to find a setting that almost didn't suck, but it involved turing the low EQ up to max, and the high EQ down to 9:00, just to get a tone that resembled my original signal. The one good thing about this unit is it is very quiet, almost dead silent. I actually bought two of these units, one last year and one now. The one last year also sounded terrible, but I dumped it without reviewing because it had a lot of rack wear, so I figured any distortion I heard was due to it being old and broken. This one I have now is in pristine condition, and it sounds pretty much the same. It is from '95, so maybe it just needs calibration, but the fact that two in a row sound like this means I'm not going to invest the money to find out.
RDL ST-CL1: Radio Design Labs makes a series of tiny (about the size of a pack of gum) modules for a variety of audio utility applications. Naturally I had to try the compressor. The tone is remarkably transparent, even, and natural across the full frequency range, with no loss of highs or lows. The noise level is about average compared to many pedals. The one big down side is that it distorts very easily. It only has two controls- tiny screwdriver trim pots for input and output levels. It has three compression stages: "Comp", "Limit", and "Heavy", each with their own indicator LED, and your signal progresses through them in that order as it gets louder. As long as you dial back the input gain so that your signal stays in the "Comp" stage, there is only a very little bit of distortion. When it does distort at that stage, weirdly it's on the high notes, not the lows. As soon as you cross the threshold into the Limit and Heavy stages however, it's distortion city. I honestly think the full-frequency transparent tonal quality is good enough that this unit is worth considering for some applications, but not for anything extreme like electric bass. There is no bypass built in. Also note that it runs on 24VDC, and the stock RDL wall wart is huge, like four times the size of the audio module itself.
dbx 160XT: First, read my review of the 160A. dbx releases new letter/number names for each design whenever there is a change in the production. Their original "160", also known as the 160VU, was a very different circuit with its own unique sound. The modern "160" series started with the 160X; then they replaced its barrier strip connectors with XLR and 1/4" jacks, and called it the 160XT; then they switched the production from hand-assembly with traditional thru-hole components to robot assembly using SMD (miniature) components, and called it the 160A. Aside from those differences, the circuit design and component values are nominally identical. However the fact is that different specific components can sound different, and to my ears the 160XT sounds notably nicer than the 160A, with warmer tone and slightly fuller lows and highs. The XT has both balanced XLR and unbalanced 1/4" jacks; there is actually a very different set of components driving each of the outputs, so you can get slightly different sound qualities by using one or the other output. The output of the 160X uses components identical to the unbalanced 1/4" output of the XT, so the XT is like an X plus another variation on the sound. The differences are subtle, but worth exploring if you like this sort of thing as I do. I find that the unbalanced out of the XT has a lively quality which is very appealing. Overall the 160X/XT have a somewhat warm, neutral tone with low noise and no unwanted artifacts, and they are rugged and easy to use. It has a fixed attack which is a bit slow, meaning that it sounds quite articulate as it allows more of the initial note attack through, but if you peg it with a loud note it will allow the initial transient spike to pass and possibly clip your other gear. So that means if you want to use it as a limiter you'll need to carefully adjust all of the gain levels in your chain to make it wor |