I'm currently troubleshooting a state-variable filter I built. All of the filter types work, but the resonance pot has no effect. Tracing a sine signal through the feedback pathway, I found that it ended at pin 7 of U6 - a LM13700. This is the input to the transistor buffers, and there's no audible signal coming out on pin 8, which is the output from that buffer.
Here's the schematic I'm working from. I'm referring to U6. It looks like it is hooked up as an emitter follower. DC voltage at pin 7 is -36.7mV and at 8 is -252mV.
Should I be hearing the signal coming out pin 8?