Phil Leigh;348887 Wrote: > Ok thanks everyone... I think I get it now! > > So - does the scope plot I posted earlier in the thread look OK? It > seems to be a good squarewave with nice Gibbs ringing/overshoot and > square (not rounded) shoulders. I wonder why the horizontals aren't > more "horizontal"? - could that be indicating a power supply issue with > the DAC perhaps? Or is this another quantization artifact? > Cheers > Phil
It looks decent - much better than the first one - but it is a little odd that the tops are so asymmetrical and curvy. I played around a little and managed to produce something very similar. I had to do two things to the standard Nyquist limited square wave: I added a frequency dependent phase distortion, and I modulated the whole thing by a 2kHz tone with amplitude about 7% of the level of the fundamental. The phase distortion could come from various sources, including the scope itself, and I doubt it would be audible if its in the audio chain. The 2KHz modulation is probably 2nd order harmonic distortion. It's rather high in level - if it's due to your audio gear I would worry a little. +-------------------------------------------------------------------+ |Filename: distortedsquarewave.jpg | |Download: http://forums.slimdevices.com/attachment.php?attachmentid=6014| +-------------------------------------------------------------------+ -- opaqueice ------------------------------------------------------------------------ opaqueice's Profile: http://forums.slimdevices.com/member.php?userid=4234 View this thread: http://forums.slimdevices.com/showthread.php?t=53345 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
