Last Issue we gave the AwTAC Channel Amplifier a big thumbs up. This issue we examine its 500 series sibling, the unsurprisingly named Channel Compressor.
Review: Greg Walker
Compared to the comprehensive layout and feature bonanza of the double-width Channel Amplifier, AwTAC’s compressor is, at first glance, a much more conventional 500 series beast. The chunky faceplate sports industrial-style distressed-metal grey and silver chic and the build quality is exemplary — all through-hole, discrete components (apart from the metering) and knobs and switches that are smooth and responsive. The company’s NYC hand assembly ethos and passion for transformers and transistors is once again fully evident. The Channel Compressor is a FET-based design and is transformer balanced on the input and output stages. The side chain control element is placed after the input transformer so the input can be driven hard pre-compression, while multiple stages in both the input and side-chain circuits contain carefully tuned discrete transistor amplifiers (these also play a big part in the unit’s sound). Five rotary controls from top to bottom take care of input drive, gain reduction, release time, processed/dry blend and output gain. Alongside these are four small silver toggle switches that control a gentle high pass filter (6dB/octave below 375Hz) on the compression circuit, attack time selection (fast 1.5ms, medium 15ms, or slow 40ms), an auto release option and full hard-wire bypass. Rounding out the front panel features is an eight LED gain reduction meter with a scale from -1/2dB to -15dB.
When I first fired up the AwTAC Channel Compressor I found a ready use for it in pumping up some fairly clean drum sounds I had recorded a few weeks earlier. I ran snare and kick sounds through one unit, sometimes gated and sometimes not, and shaped the transients on both these sources while adding weight and substance to the sounds. This approach worked a treat and I soon found the AwTAC to be a great comp for electric guitars and general drum bus duties as well as bass guitars and more aggressive vocals. There’s a lot of play in the gain structures with this box so you need to experiment. The clean gain reduction is very useable though quite subtle at lower levels, but when you introduce more drive on the input things get pleasingly gritty and thick. Above unity, the drive pot introduces distortion into the compressor circuit and is very effective at delivering anything from a subtle saturated effect to downright hairy palms. The HPF really plays a big role in how this compressor behaves tonally: engaging the filter creates a bigger-than-life bottom end image; while leaving it off allows the comp to really squish down the lower registers for a more pronounced midrange focus. The three position attack switch is a little limiting but works OK for most sources, while the auto release setting yields a program-dependant response that works very well on most sources. The Channel Compressor holds its tonal balance well under extreme duress and can also lend a nice ‘transistory’ thickness to program material on the stereo bus. The Blend pot is interesting and perhaps slightly misleadingly named. In fact this pot is a feed of the direct, uncompressed signal which can be blended with the compressed signal coming through the Output pot. Both these signals are routed to an internal 2×1 mono summing bus which combines them for your final output, so there’s lots of control there for parallel processing when you need it.
Overall, I thought the AwTAC Channel Compressor did its best work in more aggressive roles with the drive control pushing the input circuit hard. For subtle and/or transparent dynamic control there are other 500 series devices that perhaps have a wider sweet-spot before saturation kicks in, but the AwTAC also performs well at more modest settings. This compressor definitely does a ‘thing’ and does it extremely well, particularly on rock and other harder styles of music where impact and a little or a lot of ‘hair’ on the source can make all the difference. With the bonus of true parallel processing and the ability to effectively dial out the compression and use it purely as a drive box, the Channel Compressor is a well thought out and tasty 500 series dynamic controller. If you like some grit in your sounds the AwTAC Channel Compressor should definitely be on your shortlist.