I am trying to diagnose a problem with a LSC amplifier. I was using a freq. sweep input and noticed than when I turned the gain up the I was hearing the sound. There is no speakers hooked up and the sound seems to be an exact replica. I did not try other sounds as it seems pretty obvious that something is making reproducing this sound and it is not coincidence.
I guess I could make some type of acoustical amplifier to probe around the circuit to find where it is coming from but besides that is anything I should look for? Maybe this is a natural thing? I suppose there is the possibility of a resistor or cap producing the sound due to some strange effect or it could be the sum of all the minute effects from each component but most likely it is something pretty straight forward(bad tube)?
Any ideas where I should start looking?
I guess I could make some type of acoustical amplifier to probe around the circuit to find where it is coming from but besides that is anything I should look for? Maybe this is a natural thing? I suppose there is the possibility of a resistor or cap producing the sound due to some strange effect or it could be the sum of all the minute effects from each component but most likely it is something pretty straight forward(bad tube)?
Any ideas where I should start looking?