hum and noise
We don t have the schematic diagram, we changed a lot from the PCB--Lite Audio, all wrong, my mate says it s a faulty pot, he says it happened before with such a brand EIZZ, but I think it s a valve. The noise is only present at the volume full down, if you raise it it disappears. !!!! Thanks for the attention.
We don t have the schematic diagram, we changed a lot from the PCB--Lite Audio, all wrong, my mate says it s a faulty pot, he says it happened before with such a brand EIZZ, but I think it s a valve. The noise is only present at the volume full down, if you raise it it disappears. !!!! Thanks for the attention.
Connect a small 10 ohm resistor between the pot ground terminal and the audio ground.
Do this for both channels. This reduces ground loop problems.
If that does not help, it is likely a bad pot. Sometimes an internal rivet connects the
pot terminal to the pot element, and there is a poor or oxidized connection that cannot be fixed.
Do this for both channels. This reduces ground loop problems.
If that does not help, it is likely a bad pot. Sometimes an internal rivet connects the
pot terminal to the pot element, and there is a poor or oxidized connection that cannot be fixed.
Thanks. The rather heavy pot, 4 sections, balanced, fell from my hands before mounting it, could have been that but at the beginning of test use did not show this problem, then it showed, but only 10 minutes after switching the pre amp on, not it s always present, can't it be the 12au7 tubes? I don t have replacement tubes to test, ordered them, in the post .....coming.