Feral,
if you've built one could you tell me which transistors you used at what gain? Not sure what other documentation you'd want other than what I've already stated. I guess I could note Q voltages but I don't have a benchmark to compare to unless I trace this SMD factory unit.
I'll try to remember to post pictures of my board later today.
It's in my last order, which hasn't arrived yet.
I mean "document" in the verb sense, and just like I said, make note of any discrepencies: If you find a faulty transistor or one installed backwards or a cold joint on one leg, if a pot was inadvertently swapped with another such as a 5k and a 500k, incorrect resistor values etc, it could be a combination of things, a "perfect storm" — I'm
very interested as to why you're getting this octave up and wish to replicate it. If it's a faulty part, replication will be impossible. However, if all parts are good, it may be possible to replicate that perfect storm. Is the octave up useable?
Even if it's not, I'm still interested in what exactly is causing a "really REALLY pronounced octave up" in your build.
Okay, pics... looking at the pics...
A100k Output looks like it has some cold joints, test with a DMM for continuity, if one of the pins isn't connecting properly, document which one, then reflow the solder there, and test with the DMM again. Mark it down in your trouble-shooting doc whether you resolved the continuity and whether that killed the octave up.
I try to mark everything down while I'm building, potential problems or parts substitutions. However, I find I'm never thorough enough as when I revisit the document later during troubleshooting, the stuff I trusted to memory — "oh I'll remember that, it makes sense" or whatever — with a time gap I forget what I was thinking in the moment. So while I'm notating the troubleshooting, I'm marking everything down and try to be even more thorough. Stuff that seems obvious or not necessary to mark down, often bites me in the butt later.
Back to the pics...
A5k High-Cut is bare-backed so put some tape on it or a pot cover to eliminate the possibility it's shorting.
SW looks like there's some solder trailing off the middle lug, but might be a reflection off the flux (now I get why everybody here is a stickler for a clean board). That could be shorting the switch.
C5 & C4 may be suspect, but I've melted caps much worse and they worked.
C9 looks okay on the solder side but the component-side shows the pad — worth checking the solder joint there.
Check all your resistor values, make sure they're correct.
I've got some parts that just came in to the local parcel centre, so gotta go pick those up. I'll be back on this later tonight.
Cheers,
FF