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September 17, 2007 - 5:34pm
#1
I need hum help
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It could be one of several things but it sounds like a bad interconnect or plug/jack. Does the problem cease when you touch or move one channel's RCA connector? If so, reverse the channels by moving each RCA connector to the opposite channel input and test whether the problem moves with the change in connections or stays in the same channel.
Also make sure your Tuntable ground is correctly hooked up the post on your amp (or phono amp). It reminds me of a problem I had once and it was a loose RCA jack.
Thanks for the quick reply! On your advice, I tried switching the channels and I tried one channel at a time, but the problem persisted throughout. I'm thinking the problem is with the amplifier, not the cables. What do you think?
Unplug everything other than the amp to the speakers. If the noise persists, it's the amp that needs service. It still sounds like a bad jack so gently work with the input jacks to ascertain whether they could be poorly soldered.
I had considered that, but the Rega P1 did not come with any kind of ground cable. The instruction manual says, "The arm earth (or ground) is automatically connected
through the arm cable screening. No other earthing should
be necessary." I'm not sure exactly what all that means, but I think it's saying I don't need a ground cable.
I'm interested about your loose RCA jack. I just discovered that if I am firmly pressing the RCA cable into the amplifier, the humming doesn't happen. But as soon as I release pressure, it can come back.
When I unplug everything other than the amp to the speakers, there is no hum. When you say input jack, are you talking about the holes in the back of the amp that the RCA cable plugs into? If so, I think you are correct in saying it is a bad jack. How can that be fixed?
Thanks again!
The Rega arm has its earth ground tied to the left channel neutral so there is no separate grounding cable on a Rega arm.
RCA "jacks" are the female portion of the connector and are typically on the amplifier. RCA "plugs" are the male portion typically found as the termination on an interconnect cable and they, natually, plug into the jacks. If you can recreate the problem with nothing plugged into the amp other than your speaker connection, the problem would appear to be in your amplifier. If you cannot recreate the problem with no connections made to the amplifier, the problem would then appear to be in the cables or plugs. Plug one cable at a time into the amp until you can create the hum. This would then be your bad connector. You should then be able to determine whether you have a bad cable, plug or jack. Depending on the location of the problem, a simple resoldering job could solve the problem. But don't attempt this yourself. You will void the warranty. Call your dealer with your findings.
From my past experience, every time I have gotten a hum it was from a grounding issue.
I could spend all day talking about Hum - Variances in center taps on transformers - eddy current pathways resitive and capacitive properties of interconnects... but I wont
Here have this
https://secure4.vivid-design.com.au/jaycar2005/images_uploaded/humloop.pdf
Trying playing a song that the sytem knows so it doesn't have to just hum and fake it. That usually cures humming.
From my past experience, every time I got a buzz it wasn't a grounding issue.
I hum ! ............ I need a bath
Dynamo Hum, Dynamo Hum, Where's this dynamo cumming from?