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Distortion from speakers - amp?

Friends, I have a new amp (Halcro MC20) and preamp (Atma sphere R13) that I have mated to my beloved Newform Research speakers. My previous set up was a Pass Aleph 5 and Blue Circle 21 preamp. While the new configuration sounds wonderful, I am hearing very audible distortion, greater with one channel. With the ribbons, it is a buzzing sound, and in the bass drivers like a feedback hum. Again, when I change the channel cable connections between the pre and amp, the sound changes sides as well. It does not seem to be dependent on volume setting. Turning it up does not increase the distortion. The preamp is stone quite but the amp has a bit of a buzz when it is on. Ideas? Thanks much.
deliberate1
atmasphere's avatar
atmasphere
11,841 posts
 
OK :) I would try a set of shielded cables just to be safe. Unshielded cables, even balanced, can sometimes pick up noise.

Otherwise I would guess that its in the preamp. If that's the case I would try moving the 6SN7 tubes from one channel to the other and see if the problem moves.
deliberate1 OP
33 posts
 
Atmasphere, thanks for the suggestion. I will give that a go. I have some other tubes which I have can roll as well. Frankly, I do not think that it is the amp or your baby. I hooked up my old componants (Pass Aleph 5/ Blue Circle 21)to the speakers and heard similar distortion - just less pronounced perhpas because less juice. Is it possible that it is the power supply or are the speakers the source?
By the way, the R13 thing is really code for all of us owners who would have a hard time explaining to our wives how much we paid for that "MP-3" player.
atmasphere's avatar
atmasphere
11,841 posts
 
Try swapping the input cables for your source and see if the problem moves. I was thinking the preamp because you mentioned that the volume control did not affect it, but if other gear behaves the same way there is something different afoot.

I've seen malfunctioning digital gear inject lots of RF noise into the rest of the system, but I would expect slightly different symptoms. You never know though...
deliberate1 OP
33 posts
 
Atmasphere, since the distortion happens with both amp/pre configurations, could the problem be with the speakers - or perhaps the power supply. I am listening to this in a new location and I am not using any sort of power treatment. Thanks for your continued interest.
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