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

Showing 3 responses by atmasphere

What's an Atma-Sphere R13?? You'd think I should ought to know that one but I don't.
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.
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...