I'm having an issue with one channel of a dual line/mic preamp. The unit is a TAB 372ds from the 1970's. It is a dual line amp that has been converted to a mic preamp (the feedback resistor has been removed- R7). I have 4 channels total and 3 work fine. One channel, however, is exhibiting a strange noise (maybe oscillation) - it sounds like a steady electronic snare drum. The channel will pass audio, but the low end is missing. I have compared the components to the other channels and they are the same and oriented correctly. I can attach a copy of the schematic (disregard the notes) and a sound file of the noise I am hearing. Any assistance in troubleshooting would be greatly appreciated. Thanks in advance.
Attachments
Start recapping the unit, first the faulted one, but once it is OK, then continue with the ones OK, because they surely will fail soon too.
Thanks - I recapped and the noise was still there. So, I replaced the components with the originals.
- Status
- Not open for further replies.