Another thought: Your scope should have a test-square-wave output on the front. It's analog and you should calibrate your probes on it using the little adjustment-screw (capacitor).
Also, something that Mr. O observed already (http://forums.slimdevices.com/showpost.php?p=348946&postcount=46) but I'd like to repeat it here because it's the 2nd more obvious part of the distortion: 1. phase distortion. When you bring that to the picture, it means that the tops are not horizontal anymore. Look at fig. 6.7 here: http://www.tpub.com/neets/book23/101a.htm You normally get this when passing the signal through a filter and the higher the order of the filter, the more tilted it gets. But where's the filter in the TACT? (a digital software filter shouldn't do that and I'm not familiar enough with DSP's to tell if they cause phase distortion like this...) 2. AM modulation. The 2 kHz modulation is obvious and this is the 2nd harmonic of the fundamental. Measuring at different frequencies will show if it's a persistant 2nd harmonic modulation. I have no clue yet where this can come from... cheers, Nick. -- DeVerm ------------------------------------------------------------------------ DeVerm's Profile: http://forums.slimdevices.com/member.php?userid=18104 View this thread: http://forums.slimdevices.com/showthread.php?t=53345 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
