Ok so first off... RCA4156's are different from RCA4136's (daggone dyslexia maaan...). I was double checking the schematic and I noticed the +20 was on pin 4... got me suspicious. Checked one of the BD's I did last night.. nope... pin 4 on the adapter definitely did not go to any of the V pins on either of the bugs.
4156's.. which is what is in the 3000.. follow the more common pinout. The 4136's ... those need the BD adapter.
So THEN.. hmmm... I realized I still had a couple of quads laying around. Both of those were straight through DIP to SOIC adapters where I had mounted OPA 4134's (quad equivalent of OPA 2134). Ok.. COOL.. the 4134's have decent specs, so what the heck.. plopped those in, in place of Z8 and Z9 (basically the main output buffer and involved in the tone control circuits).
Scoped it.. metered it.. yeah.. nothing going to blow.. let's give it a shot...
Put it in front of my 400. Remember this is the bassid child I've been beating on (no worries Kev, THIS is why we're NOT experimenting on yours). Listening a little bit. Hmm.. ok.. yeah doesn't sound too bad. But also the noise to me seemed a little higher than it should be. NO big deal... I have other options for quad op amps, now that the pinout is more standard.
BUT THEN...
On the 3000's there is a tone defeat, which punches in and out the bass n treble controls. Up until this point I've had the controls out / defeat "on". Punched in the tone controls....
KEEEERRRPOOOOWWWW!!!!!! ZAP BAM BOOM!!!!!
So said my speakers. Blew one of the rail fuses on the 400. Yiiikeeess!!! Could be something with the amp I yanked out of a container.. dunno.. gotta troubleshoot 'er.
Well, ok... I gotcha there "tron gods"... Lessons are...
1. A "3" is different than a "5"
2. Put the damn pre through some more tests before trying it with an amp
3. Damn if that WOPL can't take a beating. Just a fuse.. no worse for wear, which is cool!
Hmmm... guess I gotta go put some deoxit on Kev's potential 3000...
