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In the Forum: Audio Discussions
In the Thread: It’s mad, mad, mad... electricity.
Post Subject: Thank youPosted by N-set on: 11/16/2020
Thank you very much for all the help/advise. I'm still to investigate the problem. The working hypothesis is that my phono has some GND routing problem. Will examine it with the scope and shortening method to see if that's the case.
PP does damp its filter caps noise to GND, the info I got from PP (hope can publish):
"The charger and the input AC filter circuits both connect to incoming AC
and both are connected to ground through their filter caps and
therefore feed filtered noise to ground - where in a perfect ground
system it would disappear from our life forever as intended."
Indeed, the noise at the output of my phono looks like charging voltage of a cap input filter (5ms base = 100Hz fundamental freq):
It is NOT present at the input RCA's and varies in amplitude depending which phono input I select (shorted MM smallest, Decca cart biggest).
Will let you know the results.
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