Davidm1108- I know that I am going to get into trouble for
saying this. I am currently using M2Tech EVO USB Converter
out of PC-Windows 7. The EVO is feeding Space Tech Labs
Vacuum Tube DAC via AES/EBU Digital. Tubes are renowned for
picking up Power Supply related noise, and I have four on
DAC Balanced Output Stage, plus two huge Tubes for DAC
Rectifier. Switching Mode Power Supply Noise from PC precludes use of installed Sound Card, and DAC doesn't have USB Input. External USB Converter, with own Analog Power Supply, became a must. This applies to my type of DAC only, not necessarily anyone elses. My DAC is just simply going to sound better with external Converter with its own Analog Power Supply. It just puts an extra layer of separation between SMPS PC and DAC Analog PS. This is done out of Engineering necessity for my type of DAC ONLY! Are there Sound Cards that have Special Power Supply Filters for rejecting SMPS Noise? Some DAC's even have Switching Mode Power Supplies themselves, do they have exceptional Power Supply Noise Filters themselves? I don't know. It DOESN'T seem to be a problem with a percentage exceptionally sounding Sound Cards and DAC's. Switching Mode Power Supply is used as a means to conserve Power, and help the Environment. It does produce some noise, which must be filtered, especially when it comes to connection to Analog driven Equipment. My case is just an extreme example of this. I use external Converter, with external Analog Power Supply, out of Engineering necessity. Others WILL have different, if not better, results. It does make me wonder, though, if mixing SWPS with Analog Power Supplies does cause compatibility problems leading to mixed results with PC Audio. There does seem to be a wide mixture of results utilizing different PCs, with different DAC's, with different USB Converters/Sound Cards/USB DACs. Call it total nonsense if you want, there is still some basis in electrical theory to back it up. That is, unless you want to throw out the Baby (All Electrical Theory) with the bathwater. How do you explain ALL different results, to the total exclusion of Electrical Theory, with PC Audio? Sounds like Flat Earth Logic, and reason. Why is it that whenever anyone discusses these differences with PC Audio, it is handled here like the Spanish Inquisition? No one here DARE have a difference of opinion in Electrical Theory-Really! Hang everyone up by their thumbs? Chill out! Anyone carrying big
guns out there, keep them in your holsters. This isn't the
Wild West here. It is, after all 2011, not 1885! Don't make me sic Wyatt Earp on you, is it really necessary to dig the poor Man out of his grave?