"Inserting" KT76 Compressors

[MJKlein]

I have found that it's difficult to get enough drive into the KT76 using the standard Aux I/O channel insert technique. I'm open to suggestions because when I was using Aux I/O only, I had to crank up the headamp so high that it would clip, just to get the meter to move on the KT76. I could never get enough juice that way to use for a heavy snare compression. Am I missing some possible gain stage that exists in the insert loop?

I experimented with feeding the compressor from a bus. I pulled the input cable from the compressor, leaving the output cable connected to the Aux input as normal. I put a snare channel onto a bus and took the snare channel off the Stereo bus. Using an XLR cable, I fed that bus out to the input of the KT76. I found that feeding the compressor as such gave me tons of gain. Of course, I still had FX send control, etc. from the main channel. I brought the compressed signal back into the mix on the Aux channel. That could also be used as a form of parallel compression. I don't see any down side of this workflow because I do have the extra mixbuses to spare (I have 2 compressors), and even though the Aux return doesn't have EQ, most certainly the main channel and bus channels do.

[craigf]

Double check that you haven't accidentally engaged the pad on the KT76, and that the meter is displaying the right thing and has been calibrated (screw on the back.)

You can go setup>preamps and use the gain splitting option to expose the channel's digital trim, which can give you an extra-+18dB of gain at the top of the channel before the insert point. You might need to re do your dynamic thresholds though, and it will change what the preamp encoder controls, so subsequent changes to preamp gain will need to go via the setup>preamps screen.

I'm curious as to where the extra gain comes from when you go through a bus. In theory the channel and bus processing (eq+comp+fader+DCAs) could be adding a whole lot of gain to the signal when you go through the bus, but if they're all flat\switched out and it's at unity it shouldn't be making a difference.

Ignore the bus for the moment. Can you experiment with going chDO (pre-eq) to aux out to see if there's any difference in level at the auxOut socket for the insert setting vs the auxout DO setting?

Can you also check if you route the DO to an XLR output and see if there's any difference between a DO at TRS and DO at XLR?

You can move the tap point around to see which part of the channel strip is adding the extra gain.

You can also test Ch>bus, bus DO to TRS+XLR and compare, Ch>bus, insert (auxIO) on bus would also be useful tests to see where the extra gain in.

The problem with doing parallel compression with outboard and a digital desk is you end up with different signal paths; the wet one has more latency due to the extra DA-AD conversion, then when you sum it with the dry one at LR you get coherence issues (which may or may not be audible.) You'd need to either do an analogue loopback for the dry path to make the signal paths similar, or dial a line delay into it to compensate (probably have to burn a bus\channel for this.) Or you could try using the console's ultimo compressor (which is modelled on the Urei 1176, which is what the KT76 is trying to emulate anyway.) No extra DA-AD issues, but as it's a digital emulation it'll have its own processing latency, which could be better or worse than the DA-AD.

If you do want eq on the returns you could plug them into a spare channel, or leave them plugged in to the auxIO and get a spare channel to source its signal from the auxIO.

[MJKlein]

Thanks @craigf for taking the time to reply in such detail (I'll spare the long quote). You asked all the questions I asked myself (plus a few more) because it didn't make any sense to me either. The pads are out. I'm going to go through your comprehensive list and see what's up with the gains per stage. I'm guessing that your digital trim solution is going to do the trick, and if it does that would be good enough. As for channels/workflow, I don't really care. I only care about the outcome. I use the Ultimos a lot. There sometimes aren't enough of them and the hardware sounds better to me, as long as there is a healthy level going to it.