All of this is fine, but how does it sound?

I'm happy to report that the VCAs and control systems sound really transparent and have no annoying artifacts or anomalies. The VCAs measure very well, with a noise floor down well below -90 dBV and third harmonic distortion equally low. They are always in the signal path (the bypass switch simply sets them at unity gain) and to date nobody working here has even noticed their presence. At the top end of the amplitude range, they remained audibly clean even with a +6 dBu signal going in and 10 dB of gain in the VCA.

I'm working on a long, classical sort of synth piece that involves all 24 tracks and lots of slow gain riding over about a 20 dB range with some really extreme levels, ranging from about -60 dB full scale all the way up to 0 dB full scale (which is +14 VU in my studio). The signals are often quite complex and, er, challenging. The Mackie has dealt with all of this with aplomb, and simply never presented any problems sonically. The manual claims 117 dB dynamic range, which seems about right to me. Keep in mind that's just about the same as 20 bit digital. Not shabby.

The other sonic issue has to do with VCA tracking, particularly at low levels. The analog faders on my (Mackie) console are decent ones, and they sort of jump from "off" to about -80 VU and are a little touchy down at the bottom of the fader, but quite smooth from -60 on up. The VCAs actually are smoother and have a longer movement for their transition from "off" to -60, but the incremental steps are in fact audible. This is not a big deal at all - it is bad craft to mix in this range and the behavior is exemplary for all normal fades and transitions to and from silence.

So how does it sound? Just fine, thank you. If you can't stand to listen to this package, you've probably got a problem that we aren't gonna be able to help you with.