Author Topic: Webcor portable humming problem.  (Read 706 times)

premier72

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Webcor portable humming problem.
« on: March 10, 2016, 04:56:36 PM »
I just recapped and installed new resistors in a early 50s Webcor and the amp is quiet until I plug in the changer? Checked all of the phono leads and the rca plug and everything checks with good continuity. It is not a loud hum, but enough to notice. Is this hum normal for one of these older players? It is a model 124.

AlexanderMartin

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Re: Webcor portable humming problem.
« Reply #1 on: March 10, 2016, 05:48:48 PM »
It could possibly be bad shielding (or lack thereof) for the tonearm wires. If you plug it in and it introduces hum, I'd bet the hum is originating from the motor and the phono leads are picking up the motor hum. I could be wrong of course, where are the tonearm wires placed in context of the turntable, and is there any shielding of any kind around the wires?

TC Chris

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Re: Webcor portable humming problem.
« Reply #2 on: March 10, 2016, 11:08:12 PM »
Have you tried unplugging the motor AC supply?  If the him disappeared, maybe you've got some minor AC leakage in the motor?  And your question reminded me that I'm having a similar issue with my 1956 V-M model 566.  I replaced the filter caps a couple years back and then did the paper caps last fall.  It still had a low-level hum--louder than I expect. I will be able to investigate further when winter is over (this one lives in my garage).

And it also reminded me of a fix many years ago on a Bogen DB-115 mono integrated amp, a 6BQ5 amp from about 1957.  It was my first college amp.  It developed an annoying low-level hum that I fixed by lifting an AC line filter ceramic cap.  The amp is retired right now but I should probably pull it out and replace that old ceramic with a modern safety cap.  Maybe my V-M amp has a similar issue.  How about your Webcor?

Chris Campbell