I've finally finished experimenting around with ferrite beads on the speaker cables near the amp binding posts, as recommended on the Magnan Cables tweak page for Nuforce amps, and thought I'd report my experiences. In short: nice, significant improvements if implemented correctly. The ferrite idea came from Steve Nugent's Empirical Audio website; he sells a version as a tweak, but recommends ferrites only on the negative cable. Magnan Cables recommends a ferrite on both the positive and negative cable. I started with the negative cables only. Result: much clearer image, more detail, but bass drive seemed significantly constricted. Then I switched to ferrites on both negative and positive speaker cables (this is called a "common mode" choke). Result: clearer image, much more extended on top & bottom than with ferrites only on negative cable, and bass power & drive are there in spades. Overall, with ferrites on both + and -, the sound is snappier, clearer, more extended, and more tonally rich (tonal shadings are more clear and nuanced). I should emphasize one additional point: in my experience, the ferrites had an extended burn-in period. At first, the sound seemed actually a bit muddier; after fairly extensive burn-in (I didn't time it, but would put it at probably 75 hours), clarity, bass extension and power, treble extension and clarity all came into place. I used some old Amidon snap-on ferrites that I had in my parts bin, and I don't know their rating; regarding sizing, they fit snugly around the cables without much play. I see from Amidon's site that they sell ferrites in a wide range of ratings, and so it would be helpful if anybody following this path would note the rating they've used and report back on their experiences. My system: Vecteur D-2-->Altmann Attraction dac-->VH-Audio cotton silver IC's-->Don Allen custom tube linestage-->VH-Audio cotton silver IC's-->Nuforce 8.02 mono's-->VH-Audio CheLa speaker cables-->GR-Research Paradox 3 speakers; various power conditioners; all equipment on sand-boxes on a custom stand, with various footers as appropriate.
