Years ago I bought a second generation Cambridge DacMagic from a dude who said he liked it but it could use a better power supply. I liked it because it had 2 SP/DIF inputs (used for cd player and streamer) and balanced outs, 3 filter options, blah blah...Soon Audio Advisor started selling a Peter Madnick designed beefy low noise power supply called the P100 for this DAC and a couple of other things and, of course, I bought a couple of those (inexpensive). Sounds astonishingly great, or at least music going through it does. Seriously…Redbook upsampled for days (whatever upsampling 24/192 does…hard to understand as I'm not very smart), and in this case seems to work very well, and I've actually done an a/b comparison with a friend's MUCH more expensive and well regarded DAC and we agreed it was pretty much indistinguishable from his. I'm keeping the damn thing until it dies.