Carver C-1 Preamp Output Voltage Issue

[fhawk618]

I recently purchased a Carver C-1 preamp in excellent condition. It worked very well at first with no issues; however, it developed a low-level, high-pitched whine in the left channel, then spiked--sending the amp (M-1.5) into protection mode. The amp appears to be fine, but upon checking out the C-1, there is an extremely high 5.6-5.7V voltage showing on the left channel of both Main 1 and 2 outputs. This errant voltage is not impacted by changing any of the other controls on the unit (infrasonic filter, tone, volume, holography, etc.). The only control that has any effect is the speaker selector--when the speakers are disabled, the voltage drops to zero. Only the left channel is affected, and the voltage is only present on Main 1 and Main 2 outputs--no other outputs (tape, ext. processor).

I have been advised that this issue most likely stems from IC-7, or possibly IC-8. Any help would be greatly appreciated.

Thanks, Frank