Ok, compressor debugged. My original issue was that I had forgotten the convoluted signal flow through my switches.. It happens.. The switching for sending the signal to the insert can be switched to before or after the compressor. The sidechain can also be taken from before or after the board on a separate SC bus that can be assigned from anywhere in the strip.
I had simply forgotten that I needed to hook the Return to the Send for the signal to come out of the board's connector in BOTH modes, not just for one mode.
But I also found a PCB error in that I routed a trace too close to a through-hole and the annular ring bled over to the trace during etching at the factory. I'll need to edit the PCB file to get a little more clearance, although DRC didn't catch this error for some reason even though it caught other clearance errors. This was causing signal bleed even without power, but with power it was causing the output opamp to "fight" and draw a lot more current.
The interface PCB which contains the main interface to the bus cables as well as the muting and routing circuits seems to work. I haven't brought up the digital section yet as I need to figure out how to trigger the mute FETs without the data bus from the controller in the X2 mixer.
Ugh. Once I had a ground pour offset that didn’t get caught in DRC and effectively muted 2/3 of a circuit. I feel your pain.
Also, that level of flexibility in routing is awesome.
I've definitely found that I like certain channels with EQ/filters before compression, some after.
I didn't opt to have a ton of routing buses in the channel strip, so the compressor is positioned after the EQ section for simplicity's sale, but the sidechain has it's own bus and can be sourced from anywhere in the channel strip. I'm not sure this is ultimately more useful, but should add some interesting abilities.
Playing around with the silkscreen I made for this. I think the ink is not mixed well enough or the silk doesn't have high enough thread count because the middle lettering got smeared while the ends didn't which I believe means it's bleeding through too much.
Anyway, there's changes I need to make to the artwork so a new screen needs to be made soon once I make sure nothing else needs to change.
Tested the compressor once again after finding another issue. A ground was left of of the netlist for some unknown reason. It shows if I highlight the whole netlist, but will not show in unconnected nets in DRC for some reason. I've changed it and imported it a few times and it just won't show up.
Anyway, I manually added it to the layout and wired it in on my test board. The gate release seems to work better, but I'm having a strange issue with the gate in general.
The Range control seems to be backwards to the silkscreen on the channel faceplate and the threshold seems to be be a lot more touchy than it should be which would first indicate that they might be backwards.. The potentiometer on the SSL schematic has CW markings on all the pots, and I've triple checked that my schematic and layout follow the SSL schematic in direction.
So either those two pots on the original schematic are wrong, or something else is happening that I don't understand.
Did some more testing over the weekend. The Range and Threshold pots for the gate work backwards to the original SSL design. I've checked my schematic against the SSL schematic and it's exactly the same. I checked my layout and it follows the schematic.
So at some point SSL must have changed this, or wired it differently from the schematic.