08-08-2022, 07:11 AM
As the long departed Amie said it's a job for your scope. Go through the scope from front end to OP stage, start at V1a anode, finish at the OP. Try no input first, volume 1/4 say, then crank the volume up if you don't see anything. Set scope IP to AC, vertical amp on the lowest setting, TB to 10nS say.
Another quick way is to pull valves whilst it's on, but not the OP valve, that might be a bit scary for you though. The idea is you pull each valve in turn till the sound goes away, this narrows down your area of search.
Unusual noises are usually cracked resistors, leaky caps, leaky circuit boards, dirty valve bases, dry joints, bad grounds etc etc, but it could be anything hence the need to narrow your focus
Andy.
Another quick way is to pull valves whilst it's on, but not the OP valve, that might be a bit scary for you though. The idea is you pull each valve in turn till the sound goes away, this narrows down your area of search.
Unusual noises are usually cracked resistors, leaky caps, leaky circuit boards, dirty valve bases, dry joints, bad grounds etc etc, but it could be anything hence the need to narrow your focus
Andy.
