Mains frequency is either 60Hz or 50Hz depending on which country you are in. In an ideal world there would be nothing else there but unfortunately the amount of radio frequency pollution around means your house wiring acts as a giant antenna and passes this junk along with the 50Hz to the PSU. The non-linear PSU supplied with the SB3 uses a relatively simple electronic circuit which not only passes on the junk but also creates high frequency noise of it's own. The digital circuits in the SB3 will be affected by this and cause an increase in jitter, making the DACs work harder or start corrupting the digital stream. Digtal circuits are very sensitive to high frequency noise because that is the region where they operate.
The linear PSU overcomes this by using an old fashioned transformer to step down the voltage and produce a 'floating' mains - no direct physical connection between the supply and output. The AC output from the transformer is rectified, regulated, protected and smoothed so there are minimal mains born nasties and no induced high frequency noise from the electronics. All high quality CD players and DAC's pay great attention to the PSU which can account for 30% or more of the cost. Some DAC's have independant power supplies for each stage - Audio Synthesis DAX Discrete for example. You could of course ask what happens when you rip a CD with all the HF and digital noise that is flying around the PC but that is probably better left to another thread. -- Heuer ------------------------------------------------------------------------ Heuer's Profile: http://forums.slimdevices.com/member.php?userid=2543 View this thread: http://forums.slimdevices.com/showthread.php?t=18491 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
