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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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21st Nov 2009, 4:27 am | #1 |
Retired Dormant Member
Join Date: Nov 2009
Location: Florida USA
Posts: 69
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Humming noise question
What causes a humming noise and a electrical tingle in my fingers when i touch the metal under the tone arm?
Every now and then a loud static comes across the speakers then goes away when I shut off and turn back on the power switch. |
21st Nov 2009, 10:57 am | #2 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,526
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Re: Humming noise question
The humming noise is probably caused by 60Hz pickup in the cartridge wiring from the proximity of your fingers (the rest of your body has capacitive coupling to AC mains fields ).
The tingling suggests that the metal under the tone arm isn't grounded. This may or may not actually be a fault- it depends on the design of the record deck and amplifier system. Fingers can actually sense a slight tingling (as a sort of "stick-slip" feeling) at leakage currents well below any danger level. For safety's sake it would be prudent to have it checked, though. The loud static noise IS a fault. Could be caused by various problems, though, so hard to suggest a cure without more information. Also a pain to sort if it's only intermittent 'cos it'll never happen while a tech is looking at it! Chris |
21st Nov 2009, 4:08 pm | #3 |
Retired Dormant Member
Join Date: Nov 2009
Location: Florida USA
Posts: 69
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Re: Humming noise question
I was thinking maybe I should change the cartridge wire all the way down to the amp?
I also noticed this hifi is a 2-prong power supply. Do you think it would be wise to install a 3-prong grounded cable. This way the record changer is grounded as long as I attach the ground to the changer motor. |
22nd Nov 2009, 12:06 pm | #4 |
Moderator
Join Date: Feb 2006
Location: Wembley, Middlesex
Posts: 7,219
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Re: Humming noise question
I would seek advice from an engineer in the USA. I know that in Britain and possibly Europe, some sets were made with their chassis connected to one side of the mains (They were designed with safety in mind though) and these should NOT be grounded
But I dont know what arrangements were made in the USA. |