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amp noise with Quad 909-help needed

I have a new Quad 909 SS power amp. It is great to look at...but makes audible hum plus some FM radio noise, even when no premp or source component is connected to it. It has a two-prong IEC inlet, so I guess I cannot even try the cheater plug. I tried different power outlets, and conditioners at home, none gets rid of this hum. I also tried different power cords. I have two tube integrated amps, they are both much more quiet, even on 95db speakers! Any experience on common sources of hum in SS amps, or specifically Quad 909? ,and what to try next? Thanks in advance for any suggestions.
mercurypdx

Showing 1 response by bob_bundus

bob_bundus
1,834 posts
 
The two conductor line cord suggests there's no ground. Perhaps try grounding the chassis with a separate wire?
Also try reversing the AC line polarity.
This last idea seems radical & shouldn't be necessary, but perhaps try a line isolation transformer?
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