Another Peavey Phaser question

[glebert]

Working on a friend's Deuce VT. No Phaser effect. If I probe the oscillator output U12 pin 6 it is stuck at low voltage rail. If I probe U11 pin 6 it seems like the oscillator starts to run, but very slowly (about 1 beat per second) and the voltage is only going to the low rail, never high. I've swapped some of the OTA parts around and it hasn't made any difference. I found other threads that mention replacing the tantalum cap on the oscillator circuit, is that where I need to go next?

Thanks in advance,
Greg

Peavey-Mace-Deuce-VT-Schematic.pdf

[glebert]

Should add one more thing that seems odd. Pin 5 of U11 and U12 (which I think is a bias input) is at negative rail voltage. This make sense to me on U12 since the output is low, but on U11 I would expect it to be ground. Without a data sheet for these parts, and no experience with OTAs I will admit that I am a bit clueless.

Don't know that my schematic upload worked, here is a link to it as well. http://www.thetubestore.com/lib/thet...-Schematic.pdf