Turntable background hum

Whiskyguy

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Hi I have a quick question. I have just got back into vinyl via a Planar 3 thru an ArcamSA20 and delighted with the matchup.

One thing I have noticed is that there is a bit of background hum present when no music is being played and the amp is set at higher volumes. I pulled the phono cables and even with no signal there is a different white noise present on the amps phono channel at higher volumes.

Is this all normal? I suspect the hum could be caused by dirty mains, or the deck being too close to the amp, but I didn’t expect the amp to produce random white noise with no input.

Any pointers gratefully recieved!
 
assume 50hz mains hum is TT grounded / earthed correctly to amp/phono stage
or try moving the TT further away from the amp
 
Check that the TT is corrected grounded to the SA20. I suspect it is, given your adjectives.

You need to consider that whereas the SA20's specified Signal/Noise ratio (A weighted) at 50W, ref. 1V input on line level inputs is 106dB, its Signal/Noise ratio (A weighted) at 50W, ref. 5mV input on the phono input is 80dB. -80dB is well below the surface noise of the LP and the S/N ratio of the cartridge, so that I would not expect it to be audible during LP replay. If it is, double check the TT grounding.

If it's only "a bit" of background hum "at higher levels", even when you "pulled the phono cables and with no signal", then it's probably the normal level of hum of the SA20. If you can't hear it at your normal listening position and normal volume setting, you can ignore it. Also if you can only hear it when explicitly looking for it and not during normal LP replay.

I suspect that the only way to lower the hum further is to purchase a separate higher quality phono amp with a better signal / noise ratio. This quickly gets very expensive.
 
Rega hum , common design flaw for several decades
Rega is not grounded through a ground wire but through the RCA shielding ( 2WIRE )
every other TT ever produced has a grounding wire you attach to ground on your amp or phono
stage ( 3wire ) 2+ground
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Rega hum , common design flaw for several decades
Rega is not grounded through a ground wire but through the RCA shielding ( 2WIRE )
I agree that the Rega arm grounding design is a weakness, but it doesn't universally produce a practical problem. It depends on what other equipment you have, and it doesn't always produce hum. With my Audiolab equipment, for example, the RCA-grounding of my RB300 arm produces no audible hum at all.
 
Weakness not to accept a global industry standard used for several decades on millions of pieces of hardware Bit like buying a car designed to run on mushy peas & not petrol
 
Weakness not to accept a global industry standard used for several decades on millions of pieces of hardware Bit like buying a car designed to run on mushy peas & not petrol
If you could make a car to run on mushy peas, you could make millons! :)
 
I agree that the Rega arm grounding design is a weakness, but it doesn't universally produce a practical problem. It depends on what other equipment you have, and it doesn't always produce hum. With my Audiolab equipment, for example, the RCA-grounding of my RB300 arm produces no audible hum at all.
Same with my Rega RB300 to Cyrus. No separate earth, no hum.
(Seen it reported as a problem before now though).
 
Rega planar 3 with Yamaha A-S2100. I use the built in phono stage, sound is brilliant and no hum.
 

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