Humming and static noise, Plinius SA 100 MkIII


Hello. I am currently using a pair of Plinius SA 100 MkIII's as mono blocks to power my B&W 802D's. First the amps have a slight hum when on and sometimes they are very quiet. More importantly, when I turn the volume up all the way without a signal from source, there is a very noticable high frequency hiss like radio signal distortation at the speakers. I have tried many things including changing preamps, cables, cords, etc but nothing worked. These amps generate 400 watts as mono so with the volume turned up all the way the noise may not be abnormal.

I would appreciate if any one with similar issue has an answer for me. I love the amps but the noise level is a bit too high. Note: in normal listening volume the noise is very low and not noticable at all only at vey high levels the noise is very noticable. Thank you.
espoverload
Plinius amps are noted for hum/noise problems. I had a friend that had these feeding Arial speakers. The hum was awful. He was told by Plinius that they are investigating a fix.
Update: I did everything evrybody suggested and still have the noise even with some tubed amps with volume control which don't need a preamp. I changed power cords and interconnects as well with no luck. Also disconnected the cable TV, etc. The tubed amps have only 18 watts per channel so the noise is less audible but not as much as 400 watt per channel Plinius. Any other suggestions. Thanks
Maybe it is time to think about your source of electricity. What other things do you have on the same line? I have both dedicated lines as well as regular outlets in my audio room. While I do not have an RFI problem such as yours, the dedicated lines are definitely quieter than than the regular outlets. FWIW.
Plinius amps do have a very high background noise. All of them! I had my combo sent back, they lowered the gain. They also told me, if they lower gain at power amps(rca 32/ xlr 38), the sound they strive for, is not possible. No preamp can change this.
I used SA-102 and SA-250mk4. They sound very good, but this is either something you have to live with, or sell and buy another brand. Oh, the transformers hum, is also typical but not constant.
I noticed all suggestions, i am sincerely honest. This is not a problem outside the amp, it is the amp. I had so much argumenst with mty amps, the store even bought one back. It is accoring to email respons with Plinius, same with new amps. They told me, if i could not accept the SA-120 and 250mk4, i would not accept SA-103 and Ref amp. I bought krell after. But i have moved on. Krell is not not close in signum. maybe you should listen to older Classe gear or Macintosh. Your call!