I just noticed your response with that highlighted section. If you read my previous posts here, you will note that I specifically avoided suggesting to anybody (on the Linn forum) that it would make any difference to the sound quality of their systems, as I suspected that it would be highly dependant on the local circumstances (where it is WRT their HiFi sockets) and I didn't want to encourage lots of folks to waste their money on something that might make no difference (in fact, from memory I didn't even start that thread). At that time, I did actually think that replacing all the SMPSs in my lounge made a slight difference to the system's musicality (which is why I later privately suggested to a few folks that might want to try them) but at that time, I did not want to state that claim on the public forum (over the years, I have actually avoided stating my thoughts on subjective sound quality of products; I've always tended to stick to technical observations and to keep my opinion on sound quality to myself).Ron The Mon wrote: Re: Apparently no Musical Method of Evaluation?
Yet just over a year ago you wrote on the Linn Forum about the Friwo power supplies (emphasis mine):
"Of course, the main issue I was trying to address was not the noise coming out from the DC side, but the noise coming out from the other end; the noise that these SMPS spit back into the AC mains wiring (which, in turn, can act as an antenna and thus cause significant radio interference); that was my entire reason for seeking these out. I doubt it much matters too much if you feed a switch with a slightly noisier supply (though to be honest, I've never compared supplies by listening to music, so I really can't say, one way or the other), but noise can never be a good thing, so it can certainly never do any harm to get rid if it."
Others tried a FRIWO (and I loaned a few out) and did find that it did make a difference, so that was all quite interesting evidence that they are at least worthy of consideration. Of course, forgetting the ones in the lounge for a moment, I have since also found that a FRIWO fed GS108 does sound better than my D-Link managed switch (despite them being quite a distance from my DS) so that is yet another interesting finding (though that was changing two devices at the same time - both the switch and its PSU - so again, I haven't made any claims as to exactly what changed the sound; just that I need to do a lot more investigation into exactly what's going on and what making that difference).
As you can see from my posts of the screenshots (at the end of the previous page) even a pretty decent SMPS produces quite a lot of spikes; you should see what some of the less respectable ones put out! None of this can be really be considered as being a 'good' thing; the question is whether it has any impact on a music system (but in general, there sure is no harm in removing it as many linear regulators beyond it will let switching spikes 'pass through' them). Back to HiFi and in general, I'd say that over the years, I've managed to improve the sound of my system really quite significantly; most individual changes have been small ones (including my SMPS noise jihad and my bespoke mains supply) but I know for sure that the cumulative results have been significant and thus well worth all the hard work (and hard spend, in some cases). :-)
Incidentally, for another project that I am working on (which has nothing to do with audio), I can find no SMPS units with low enough ripple and noise to avoid causing me nasty problems, so I am having to build a triple rail linear supply with +5, +12 and -12 Volt outputs (which will easily be an order of magnitude quieter in terms of ripple, and virtually silent in terms of 'spikes') so even the nicer 'frame' SMPS units (costing < £100) are actually quite poor performers (in terms of ripple) when compared to a well designed linear supply.
Bri :-)