Taken from TapeOp issue #101 (and if you don't subscribe to TapeOp, you damn well should!)
AwTAC (Awesome Transistor Amplifier Company) of New York is quickly proving itself as a manufacturer with high standards. Since the introduction of its Channel Amplifier [Tape Op #93] three years ago and their Panner module (which adds a stereo- panning summing bus to the L/C/R bus in the Channel Amplifier, or works as a standalone panning/summing bus to turn select 500-series racks into summing mixers, one channel at a time), the guys at AwTAC have been busy applying their "no sonic compromises" design philosophy to their new 500- series format Channel Compressor.
The single-space unit is a mono FET compressor with seemingly-normal front-panel controls. Continuously variable knobs are provided for Reduction, Release, and Output, as are switches for bypass, auto-release, and detector high-pass filter. A three-position attack-speed switch and unique Drive and Blend knobs round out the controls. The compressor behaves in a soft-knee fashion, easing from a 1.5:1 ratio up to 10:1 (and at times, beyond). There is also an eight-segment orange LED meter for indicating gain reduction with an extremely useful range of -0.5 dB to -15 dB.
The Channel Compressor's Drive knob is essentially an input and distortion control that drives the input circuit, largely affecting the sound of the unit, making for really great tonal options. Drive can impart useful "grit" - from almost nothing to a very aggressive and very cool sound - that is somewhat independent of the onset of compression. The Reduction knob increases gain reduction (compression) and functions as one would expect, while offering a large range of subtle control in the lower settings. Like the EQ settings on AwTAC's Channel Amplifier, Reduction can be turned all the way up (for maximum gain reduction) without the resultant sound "folding" at the most extreme settings. The Channel Compressor's detector HPF seems to operate at a much higher frequency than similar filters in other compressors, and its impact is not at all subtle. Engaging the filter makes for a much smoother compressor action with all types of signals. Same goes for the auto-release switch; when it's enabled, the compressor action becomes smoother and more musical. This, coupled with the detector HPF, makes the Channel Compressor beautifully transparent in its compressor action, a feat not easily achieved with other units - even when the Reduction control is maximized. In this case, the Attack switch gives you a few options for shaping the aggression, but generally speaking, this setting will level a vocal, a bass, or a bright, spanky guitar in a way that few other compressors can.
But have no fear, compression junkies! Leave the detector unfiltered, speed up the release time, dial in some Drive, and you have a wonderfully aggressive "grit machine." Vocals can become much more energetic, and drums and bass can sit in a semi-fuzzy puddle in just the right place in a mix with these kinds of settings.
Another interesting development courtesy of the AwTAC team is the way the Blend and Output controls work. The Output control is exactly that - an output level for the compressor. While the Blend control is an output level control for the dry, uncompressed output fed from a discrete amp in parallel with the compressor circuit. This way, parallel compression is achieved the same way it would be with two faders on a console. There is truly a blend of wet and dry signals that react the way they would on a console - and not just a sweepable balance between the two, as is found in most other units with a similar feature. Output and Blend are extremely interactive, and because of this, setting the two knobs can take a little getting used to, but the resulting compression behavior is fantastic.
A quick word about the LED metering too - there's a half dB measurement on the meters. I find this remarkably useful. There's a famous compressor with an LED meter that starts at -1 dB, and for years, I've sworn that I can hear that compressor working before it actually meters 1 dB of reduction. Kudos to AwTAC for taking this into consideration. Another interesting feature of the AwTAC meter is a slight "flickering" of the meters in the compressor action, most noticeable with a lot of gain reduction happening. I can't think of any real, practical use for this, but it just seems kind of cool and amusing to me. One more thing that just kind of reminds me that music is happening.
The sound of the Channel Compressor is absolutely gorgeous. It retains a beautiful, almost "woody" kind of tone that I appreciate from equipment like the revered Nyquist converters in the iZ Technology RADAR [Tape Op #56], for example, or much of Manley's highly-regarded tube line. Hi-fi, but extremely pleasant, musical, and not at all harsh. The sound of the unit is apparent, but it's not something I would take out of the circuit at all. In fact, I want 24 of them wired right up to the output of my converters!
In terms of compressor behavior, this has got to be one of the most versatile dynamics processors I've ever used. While low action, subtle compression can be effective with the AwTAC, this thing really seems happy doing lots of gain reduction. But doing lots of gain reduction with the Channel Compressor isn't the same as doing lots of gain reduction with most other units. The Channel Compressor seems to have a wide berth, and it's hard to make this thing completely cave. I'm not one to constantly blow up everything I run through a compressor, but this compressor is perfectly happy doing its job at a steady pace of 6-15 dB of gain reduction without sounding like it's destroying the source. Of course, whacky time constant and Drive control settings can get it there, but careful use of the detector filter and auto-release make this thing a beautiful addition to the realm of available 500-series compressors, the likes of which I have not yet heard.
All in all, the Channel Compressor is easily one of my favorite compressors - ever. It has everything I love about FET compressors and none of the things I dislike about them. And it has everything I love about optical compressors and none of the things I dislike about them. It has the in-your-face speed and texture of an 1176 or an ADR Compex; the easy, forward-pushing placement of an LA-2A or LA-3A; and the dynamic control of classic broadcast vari-mu and FET limiters like the Altec 436C and the CBS Volumax - all with a very pleasant and useful tone and a nice set of features that make this an extremely versatile and flexible unit. As exemplified in other AwTAC products, the build quality of the Channel Compressor is solid. The unit has a two-year warranty, and it's built of almost entirely American-sourced parts by a small company in New York.
REVIEWED BY CHRIS GARGES · MAY 15, 2014