Think You Don't Need Another Hardware Compressor? Check This Out!

April 15, 2021 William Wittman

In this article William Wittman who usually prefers FET over VCA compressors test drives the Daking Comp IIT, a VCA bus compressor. Find out whether it can do what his preferred Compex compressor does on the mix bus.

Almost everyone I know who mixes pop music does so through a stereo bus compressor. I certainly do, and have done since the mid 1970s. And this application is, naturally, amongst the most critical of choices as it affects every element of your record, whether for the better or the worse, and we certainly hope for the better! So this is a choice I make very carefully.

My long time favourite for this application, and the choice I’ve made since virtually its appearance on the market, has been the Audio&Design Manufacturing F760x-rs Compex compressor. It’s part of the sound of most of my records for decades and I have only rarely been swayed to other choices, mostly by necessity when a Compex wasn’t available or if I’m working entirely in the box for practical reasons. But one of the few examples of an alternative that I have comfortably and happily used is the Daking FET compressor (either the original 91570, which I own at home, or the later FET II iteration).

Geoff Daking knows what he’s doing with his gear, and, in full disclosure, Geoff and I worked together at several studios, so I know that he not only comes at it from a smart design standpoint but also that he has the studio engineer background, and good taste, to make products that just sound good. So when Geoff told me about his latest design, a VCA based model he’s calling the Comp II, I was naturally interested to check it out.

Now it should be said here that I am, in general, a skeptic about VCA based stereo compressors for overall bus compression. Yes, yes, I know that the SSL compressor is the compressor of choice for so many great mixers, but it’s never been a favourite of mine. There is something kind of ‘spongey’, to me, in the way that VCA comps tend to behave on an overall mix that I just don’t find myself liking. It’s a character that kind of purposely draws attention to itself and you either want or don’t. I generally don’t. What I am looking for in a stereo bus compressor is that ineffable quality we often call “glue”, but without it producing a noticeable pumping or breathing unless I am purposely going after a kind of obvious effect a la The Raspberries in 1972. That happens, but not a lot.

But to come back to the FET II, I know Geoff shares my feeling about this and has designed the FET II to ‘sound like a FET compressor’ but with the precision and reliability of a VCA based design. Matching FETs is a difficult and somewhat unattainable task; and this presents some real issues when one wants both sides of a stereo device to truly be the same.

One major point along those lines in the design here is that Geoff has elected a feed-back architecture whereas most other VCA compressors are feed-forward. Add to that Daking’s Class A discrete amplifiers (based on the stellar and much revered Trident A Range) and, as Daking puts it: “Without a long technical discussion, the advantage of Class A circuits is the elimination of crossover distortion. Engineers agree that Class A amplifiers just sound better.” And I quite agree.

Additionally, the COMP II is available (as the COMP IIT) with Jensen transformers on the inputs and outputs adding some additional character and, in my opinion, some helpful band limiting that only serves to increase that feeling of ‘analogue glue’ that I’m after. It’s the transformer model I’m testing here.

Getting Into It

So with a healthy mix of skepticism and enthusiasm I set up the COMP IIT so that I could compare it to the 91570 compressors on a mix. One has to say that the controls here are quite different, with the COMP IIT being intentionally much simpler, not to say stripped down, so making absolute dead on settings comparisons is difficult or impossible. But I was certainly able to both come close to the settings ballparks, and, more important, to get a good sense of what the differences are, or are not, in the feeling of what the respective units do to a mix.

It should be noted that both compressors have a setting that is based on the Auto Release time of the aforementioned A&DR Compex (Auto on the COMP II, E on the 91570) so I am already starting very much in my personal comfort zone. It’s a super useful setting that responds to level and time envelope of the mix to vary the release in a way that’s always felt very musical and unobtrusive to me; it’s my default setting.

On the attack side, the older FET compressor has a lot more choices but the COMP II settings seemed to me to be good solid, again simplified, choices.

Ratio, once again is simplified on the newer unit, reduced to a choice between Compress (4:1) and Limit (14:1). I’d personally rarely want to use Limit on a stereo mix but I know a lot of people who use the SSL bus compressor at 10:1 but only tickle the gain reduction, so you have that option here if that’s your working method. On the other hand, I found fast attack and the Limit mode fun, and useful, on a parallel drum group, for example, where I really wanted a squashed, pumping, exciting signal to mix in behind the straight drum sound.