So my Total Recall build is back to haunt me again. I set about biasing the 2nd BBD after a halted first attempt once my replacement for a faulty feedback pot showed up only to discover that I had no delay output whatsoever. I traced the drop back to the NE570 and checked the voltages, all were spot on except 5 6 and 7, which were 12v, 11v and 0.7v respectively (way off). I couldn't figure it out as everything else checked out, so I assumed the IC was dodgy and ordered a replacement.
Replacement NE570 shows up, I get delay output for about half an hour, then nothing again. Again, NE570 was at fault. WTAF etc.
So, now I have a pair of Philips NE570s and it's been flawless since.
Two dying seems unlikely to be bad luck, and voltages check out everywhere else. Nothing feels warm to the touch, so I don't think there's too much current moving through it either.
Anything else I should check? Wondering if there's a dodgy batch of NE570s out in the wild somehow?
Also, I should add that the delay output is WAY cleaner with the Philips ones