Same here, sorry Phil. Will start a separate thread next time and stop off-topic posts here.
Actually, I have been thinking about your problem. My observation from your photo's is that the tops from the 5th-7th harmonics are clearly missing from the square wave. As the fundamental was 1 kHz, this is the harmonics at 5, 7 and 9 kHz. I also read that you checked at different amplitude levels and frequencies and that the pictures were the same. I would propose this: 1. check those pictures for the different frequencies again or may be you remember this detail clearly still. If that 5th-7th harmonic is still the missing, it is not frequency related but algorithm related. If it's also the same for lower amplitudes, we can assume that it's a core-bug in the algorithm and not just an amplitude-related artifact of overflow etc. 2. I am still curious on the TACT picture of a pure sine 21 kHz signal because it will show what the TACT does with signals at the limits of the 44 kHz sample rate. I mean, it will up-sample it, after which it isn't close to the limit anymore. The question is if distortion appears before, during or after the up-sampling. If we see any distortion here, it would point to a bug before or during up-sampling. 3. test with a 21 kHz sine but in a 48 kHz sample-rate file. Again for 96 kHz rate. Just to make sure it isn't a frequency limit. 4. Did you do the 1 kHz squarewave with 48 and 96 kHz files? I assume the TACT up-samples to 96 kHz? And I assume it doesn't up-sample if the input is 96 kHz already because I wouldn't know how that would be done. This will show several things: The middle of the squarewave isn't the 5th-7th harmonics anymore because we go beyond the 11f harmonic for the higher sample-rates. So, if it's still missing the "center" tops instead of the 5th-7th tops, the error is independent from input-signal If the 5th-7th harmonic is still missing (the flattened part moves left of center square-top), we must re-evaluate our thinking ;-) A final set of test-signals would be a 10 and a 12 kHz squarewave as 44 kHz sample-rate. The 10 should show one big valley between two tops and the 12 kHz should show... a sine? See if there still is that same distortion. 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 audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
