Ocelot - 0v to Pin 1 of IC5

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j_m_earley

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Hey all. First time long time. Recently completed the Ocelot Octave, or so I thought. I get signal and a hint of octave from Oct 1, but that's really about it. From what I can tell, the issue is with IC5. I've tried troubleshooting it a million different ways, but nothing has worked. There are no shorts. The other pins are getting power. Swapping in a different IC produces the same result. I've re-soldered the socket. But that pin is causing a cascading effect where none of the other ICs are getting adequate power, so this octave pedal just isn't octave-ing. One thing to note: pin 8 was also not getting power, but a jumper wire from the DC jack addressed that. That's when my pin 1 issue started. It was reading 9.5v before, which is too high, but better than 0v? Any advice would be greatly appreciated!
 
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Do you have continuity with IC5.1 and ground? If not, how many ohms between IC5.1 and ground? What about voltages at IC5.2 and IC5.3?
If IC5.1 is ~0V, then it is basically shorted to ground.

If you pull IC6 from the socket and measure the voltage, what do you get? (That helps to narrow down where the short is coming from)

Easiest possibility that I see is a short between pins 8 and 9 of IC6 (solder bridge on the solder side, or worse, a solder bridge
that's flowed underneath the socket). With IC6 out, you should measure continuity/ohms to ground around 8/9/10/11.
My guess is that things are shorted pretty hard which is pulling enough power to brown out the rest of your ICs.
Another test, if you don't find anything with the stuff I mentioned already - what's getting warm/hot when you have it plugged in?
 
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This was pre jumper wire. I just shoved it in the closet after working on it for hours, but will add more photos when I pull it back out and tear it down. I wasn't noticing any shorts when I was poking around with the multimeter and IC5.2 and 3 were getting 9.5v
 

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I could be wrong, and it's possibly the wrong part of the circuit to be causing
your problems, but I think D1 and D2 might be in backwards.
(Those russsian germaniums have their bands on backwards - measure to be sure)
A lot of the times in these circuits it doesn't matter since they're symmetric
clipping diodes so it doesn't matter which one is which way - but for this
circuit, it matters.
 
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