Just finished M-125 autobias boards. Was a bit harder then I anticipated, I don't see much feedback on installation, but fit is tight. If you choose to try, my advice is First remove C6 & C8 coupling capacitors and sit as close to board as possible when I assembled the M-125 I kept them fairly high, I also covered them with heat shrink tubing. Could it be possible to substitute a small capacitor for C6 and C8? Second, Keep wires longer then you think for connections between A/B and driver board, I had redo 2 as they were too tight though I had plenty of lead. Third, I soldered all the wires on the bias board, then attached to driver screws, made rest of installation easier. Just my thoughts and I did not see any other feedback. I had all blue lights after installation. Nice soft start up. No listening tests yet. I am an experienced kit builder but by no means an engineer, so it is possible for casual builder.