Which A-138? You've got two, and only one of those should be for audio, the other (linear) one is tailored for CV/modulation mixing. They deal with gain differently...the exponential one raises and lowers levels in a way that our hearing deals with apparent loudness (the Fletcher-Munson curves...look 'em up) and the linear changes gain in a purely linear manner across the entire input pot taper.
The layout is sort of crap, also...very confusional as to signal flow across the patchpanel. I'm going to tinker with that...
EDIT: OK, hopefully this build will actually show up. The "screenshot" function is acting pretty wonky right now...
Aaaaaaaand nope, it's not showing up. This'll have to wait until that function starts working properly again. However, I did a major-type rework of the build; since you mentioned you were considering tossing the Doepfer modules, I really dived in on this and tried for more functional density. UNFORTUNATELY ModularGrid is having other ideas here...
(Monday evening) Ahhh...the screenshot function is working again! So...
BIG reworking on this...the main thrust was to boot everything that didn't have sufficient functional density. If you're going with a 2 x 84 cab, then it's imperative that you maximize the amount of function you can cram in. So this thing got MAJORLY changed around...let's have a look...
Top row: first thing there is a neat little Cavisynth slew gen + buffered mult. And yes, this will likely have enough CV destinations that the buffered mult IS needed. Like, for the Quadnic...still there, but now paired with a little Doepfer 4 x 1 mixer that'll allow you to sum the Quadnic down with total control over the levels of the oscillators. Yeah, it's got a summed output, I know...but this offers more subtlety. Original Plaits = gone, replaced with TWO 3rd-party builds of the same. And beside this is both a waveshaper AND a suboctave divider in the Tiptop Fold Processor. Dreadbox mixer/multimode VCF next as an "in general" VCO mixer + VCF (highpass is super-useful here), then there's G-Storm's version (with another 2-input mixer) of the original ARP Odyssey VCF, and a Nanorings...yep, another 3rd party Mutable module, saving more space. Last up is the 10 hp version of Mutable's Veils for CV-controlled final mixing.
Bottom row: kept the A-118, Marbles goes next (because it uses the A-118 for random signal sources), and then I dropped in a 4ms Quad Pingable LFO. These are way nifty...they have a maximum cycle period of over 70 minutes and on the top end, they clock up to 500 Hz, so if you needed an AF mod source, there you are. Roti Pola next, mainly for mixing and polarization of your QPL. Beside that are two Antumbra VCAs (identical to the Veils VCA). Then the envelope section...I went with a Quadrax for the 2-stage loopables, and an Intellijel Dual ADSR for your four-stage envelopes for the final VCA and your VCFs. The very end of the audio chain is next to this...the Stasis Leak offers reverb, chorus, and a tap delay, plus it's a mono-in stereo-out device that can "stereoize" your signal...which goes right to the Happy Nerding Isolator, which also has your final stereo level control, and which has transformer-balanced 1/4" outs.
Now THAT'S got some beef! By yanking a lot of the sparser Doepfer stuff and shooting for more interconnectivity between SETS of modules, this is now one helluva potent 2 x 84. There's now ample modulation sources for the upper audio row, you have FX, stereo out, more VCAs...well, just MORE, really, which was the point of this rework.