hum noise

[admin_exported]

I have the Usher pre amp 307and power 1.5 combination connected to Arcam 73- there is the constant hum noise. I could lessen the noise but not completely no matter what I did by disconnecting all other gears.

Eric

 

[JoelSim]

Have you tried moving cables away from each other?

 

[Anonymous]

Yes it has been done.

I had to use a cheater to reduce the hum.

Thanks

 

[Anonymous]

Hi.

I have cured the hum through my record deck by earthing the the record players metal frame with the pre phono amp case. The hum disappeared totally. Does the hum stop or reduce if you earth the record deck by touching the arm or a metallic part of the deck? If so run a piece of wire from the decks metallic case to the amp/pre amp.

Regards.

 

[Anonymous]

hi Eric,

i run the p307a / 2x R1.5 in mono. if the buzz/hum ranges from the mid to the tweeter, the pre amp is more than likely the cause as it was with mine. If you bridge your amp the sound will become more prominent. the easiest fix is to buy an attenuator around -6dB and fit this to the interconnect at the power amp end. this will lower your signal/noise ratio and truly makes a profound difference. secondly not sure if its the same over there as it is in australia but clear a small patch under the chassis of the components and connect this to a star patterned ground you should be able to earth this through a spare wall socket.thirdly if there is a buzz coming from the amp itself this is coming from the transformer, if your confident open the top of the amp undo the transformer and fit a high temp industrial rubber mat under it these have been known to go into vibration. i have done these and more and have heard a large improvement in lowered noise floor depth and coherence. only do these if you feel competent enough.

regards

 

[whiskywheels]

Funnily enough, I noticed yesterday that my CA 640P causes a faint hum and buzzing through the speakers. This disappears when I select a different output on the amp. I use it with a Rega P1 turntable, and find that the musical quality is superb.

So, is the first thing I should try to connect an earth between the turntable and preamp? Any other suggestions? Is this level of hum normal?

 

[whiskywheels]

Hmm, just checked the Rega website and it says that the tonearm is earthed internally, and that any modifications will result in loss of warranty! Maybe theirs an earthing fault with the turntable??