plumsolly
Well-known member
I noticed yesterday that a channel on my console goes into oscillation when it is set to mic input and at it's highest gain setting or it is set to line input and is at the highest or second-to-highest gain setting. The fader must also be turned up almost to the top of it's throw. Engaging the low-pass makes it go away. I can't really hear the oscillation, but it pins the meters. Here is a schematic:
Contrary to the schematic, the chips are all 5534's and they all have 150pf caps in parallel with their feedback resistors. I replaced these caps and resistors and all the power supply bypass caps. I also replaced all the chips. If anyone has any ideas where to look, it would be appreciated. Thanks, Ben