COMP-1 | Guitar Player (June 2003)

Compressor Pedal Roundup

Compressors were first devised for the purpose of controlling the dynamics of voices and instruments. By making the loudest parts quieter, and the quietest parts louder-in effect, narrowing the dynamic range-you get a more consistent level. In the recording studio, it's usually desirable that the workings of the compressor are not audible to the listener. But when guitarists use a compressor, they very often want the effect to be audible, and some of the most popular compression pedals color signals fairly dramatically.

Studio compressors usually provide individual controls for how quickly a sound is compressed (attack), how much of the sound is affected (threshold), how intense the compression is (ratio), and how quickly the sound decompresses (release). While some compressor pedals-such as the Sabine NEX5400-offer individual control of nearly all of these parameters, the controls on most boxes adjust two or more parameters simultaneously, and some have just a single compression knob.

A good compressor can smooth out unwanted discontinuities in your playing, fatten up your tone, dramatically enhance your instrument's sustain, and even become an invaluable part of "your" sound. But what constitutes a good compressor? Should it provide subtle shaping or serious squash? Should it be transparent or have its own personality? Should it control lots of parameters, or be a simple, two-knob stompbox? Obviously, it all depends on what sorts of sounds you're hoping to squeeze out of it.

The five compressor pedals reviewed here are all very different. For example, though the Demeter COMP-1 and Electro-Harmonix Black Finger are optical compressors that use a light source (photocell or LED) to regulate gain reduction, the former uses a transistor circuit and has only two controls, while the latter is tube-driven and replete with knobs and switches. They also sound entirely different.

I tested each of the pedals with a PRS Custom-24, a Fender Stratocaster, and a G& ASAT Classic running through a late-'60s Fender Twin and a mid-'70s Marshall 50-watt half-stack. I also did an acoustic audition using a Martin DC-16RE with Schertler Bluestick electronics plugged into a Yamaha 03D digital mixer.

Demeter COMP-1 Opto-Compulator - Editors' Pick Award

Vintage Teletronix LA-2A electro-optical compressors are prized by studio buffs and lovers of classic-rock tones, and James Demeter endeavored to put the "LA-2A" sound into an affordable stompbox. The COMP-1 ($249 retail/$199 street) is truly a marvel in that it indeed captures a taste of the warmth, gentle buzz, and snappy attack of a well-maintained LA-2A. And the pedal's controls couldn't be simpler. There are knobs for volume and compression, and a side-accessible trim-pot that lets you adjust overall gain by up to 26dB. The Compress knob covers a relatively broad range of sounds-from subtle enhancement to pleasingly squashed-and it dials-in up to 30dB of gain reduction, which is pretty staggering for a stompbox.

The COMP-1 has a very gentle attack (a "soft knee" in compressor-speak), and with the Compress knob set below 50 percent, its sound is so transparent and unobtrusive that you'd be hard pressed to identify it as compression. (Although you can detect added harmonic sparkle and a general thickening.) As you get up into the second half of the COMP-1's range, the compression becomes increasingly aggressive, but even on the highest settings the sound remains sweet and very musical-particularly on single-coil and acoustic instruments. Getting this close to the sound of a vintage LA-2A is quite a feat, and most guitarists will adore the COMP-1's ability to add soul and punch to guitar sounds. Stomping on this pedal is very much like unleashing a small dose of the Electric Ladyland or Abbey Road sound upon your tone. That's delicious, and it's why the COMP-1 earns an Editors' Pick Award.

Electro-Harmonix Black Finger

The Black Finger ($298 retail/$220 street) is a total departure from EH's original, early-'70s solid-state pedal of the same name. This version is powered by two 12AX7EH tubes, and it offers significantly more tone-shaping capabilities than its forebear. The tubes, one handling compression and the other preamp gain, run on a respectable 300 volts, requiring the use of the included proprietary power supply. You can select either LED or Lamp as the light source for the attenuator, and choose either Norm (compression) and Sqsh (leveling) modes that actually affect several parameters simultaneously. There are also knobs for Pre-Gain (which adjusts the input level and determines how much signal will pass the threshold), Post-Gain (output level), and overall compression. A level LED glows brighter as more signal is compressed, and a status LED indicates when the pedal is in true bypass mode. The Black Finger's controls interact in such a way as to offer a wide variety of compression possibilities, but by the same token they require some tweaking to get the best results. Fortunately, it's worth the trouble.

Having tubes in both the compression and gain stages endows the Black Finger with a fat, warm sound. Switching between Norm and Sqsh changes the character of the compression from gentle to intense, as well as producing a dramatic change in level, and switching between the LED and Lamp modes changes the voicing from smooth and balanced to beefy and chunky. The Black Finger sounded great with all of the guitars.

MXRM132 Super Comp

Following in the footsteps of the classic Dyna Comp, the Super Comp ($70 retail/$65 street) adds an Attack Level knob to the Dyna's simple Sensitivity and Output controls, as well as a welcome status LED. The original Dyna Comp delivered thick sustain, a pleasing roundness, and lots of personality, and the Attack function allows the Super Comp to expand on that pedal's possibilities. The Sensitivity control dials-in the amount of compression, and the Attack knob seems to modify several parameters simultaneously. At moderate settings, the two knobs deliver all the classic goodies that the Dyna Comp is known for, lots of spank and pop on the lows, and glistening brightness on the highs, but the controls interact in such a way that cranking them both up causes the circuit to distort. I achieved the best results by setting the sensitivity to 50 percent, and adjusting the attack to suit a particular instrument. The Super Comp is relatively quiet until you crank it way up, and a hard-wired bypass, a nice touch in an inexpensive pedal, keeps your straight sound clean and crisp. The sound of the Super Comp continues a tradition of old-school funk, and you certainly can't beat the price.

Sabine NEX5400

The NEX-5400 ($129 retail/$105 street) takes the cake for squeezing the most stuff in a stompbox compressor. Besides having nearly all the controls you'd expect on a rack unit, threshold, attack, ratio, level, and tone, it offers both clean and effect outputs, a hardwire bypass, and dual AC adapter jacks (for daisy-chaining with multiple NexFX pedals using the Nex-Power adapter). As if that weren't enough, the NEX5400 also sports a backlit display and illuminated "Glow Knobs" for easy viewing on darkened stages.

The NEX5400's controls are not difficult to use, however, and it's easy to get a good sound with intuitive twiddling. That's partly because most of the knobs have relatively limited ranges, the Attack control is so limited that it didn't seem to have any effect at all, though the handy Tone knob does have a wide and nicely-voiced range. While the NEX-5400 doesn't offer a huge variety of tonal options, its overall sound is very clean, smooth, and pleasing, and it sounded very good with all of the guitars. In other words, it's an excellent all-purpose compressor pedal.

T-Rex Comp-Nova

The avocado-green Comp-Nova ($220 retail/$189 street) is handmade in Denmark. This pedal is extremely easy to use, and no matter how you set its three knobs, you can't get a bad sound. The Comp control dials in the amount of compression, while Attack, despite its name, adjusts both the attack and the threshold. Level adjusts the overall output level, with up to 3dB of gain boost. The pedal is very quiet in the first three-quarters of its range, and only marginally noisy after that.

The Comp-Nova's sound is relatively clean and transparent. It doesn't have a lot of personality, which can be a good thing in a compressor. For some users, the Comp-Nova's transparency will be very good indeed, particularly acoustic players who want some subtle sonic enhancement without sacrificing the naturalness of their instrument's tone. The Comp-Nova was also a great match with the G& ASAT Classic, increasing its overall sensitivity and adding appealing tonal nuances. With the Comp and Attack knobs set midway, the Comp-Nova gently thickens and smoothes the sound, while adding just a touch of shimmer and ring to the high frequencies, an effect so pleasing you may be tempted to just leave it on all the time.