2006-04-13-16:36:14 Phil Leigh: > I have a slightly off-the-wall theory that the problem with the stock > PSU is not so much what it does to the actual SB, more what it does to > other equipment
That theory is neither off-the-wall nor particularly new; others have suggested that that may be a significant factor in the improved sound many hear when, um, switching to a linear. > I wonder if the AM rejection on some gear is > not as good as it ought to be and that's what we're hearing? Hard to > prove, I know. Just a thought. Certainly I prefer the sound via the > digital outputs into a DAC using (in my case) the Farnell PSU - and > that's very hard to rationalise since I can see no theroretical reason > why the SB DIGITAL signal would be different with a different PSU... That may be going too far. I think it's perfectly plausible that either switching noise crawling up the hindquarters of surrounding equipment, or the same happening to the SB, or of course both, could be audible. I happen to think that less-noisy power fed to the SB itself is significant, because in one setup, when I was using an SB2 to feed an Arcam receiver digitally, I didn't hear a definite difference between the switcher and a linear supply; but when I moved to an SB3 (whose only parts change is reportedly a linear rather than switching regulator for the digital-out section), the difference between the sounds fed by the two supplies was clearly audible, and moreover, the sound of the SB3 plus linear was good enough that things were no longer improved by sending the bitstream through a Big Ben. It seems perfectly plausible that power supply noise which managed to get up into the digital guts of the SB might intermodulate with internal clocks in some particularly infelicitous way, changing the jitter spectrum, and that the SB3, with its linear internal voltage regulator, doesn't set as low a bar on the maximum performance which may be attained with cleaner power. I also theorize that my result wasn't swamped by the switcher's effects on surrounding equipment because it was plugged into an isolated branch of the power filter feeding the other equipment, or because Arcam do good power-supply design, or both. _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
