So how is the LP filter behavior? Something appears to be wrong somewhere. Do you have another dac to run the same digital test signal through? Measure its output with the same scope? Can you send the DSD DAC a software converted DSD signal instead of using Simple DSD Converter? Does that look okay? IOW, start thinking of ways to cross check and isolate where the problem is.
This is not a good idea. As stated in the first post, pcm2dsd was designed for PCM FS 44.1- 192kHz. It's hard to predict how it will be at other frequencies, and you give DoP and it's actually DSD but in PCM frames. And what is this modulator supposed to do with it...
So, you think its the PC or the DAC? Maybe check all the DAC power supplies/regulators for correct voltages?
If you hook up the dac output to your preamp/amplifier does it play at a normal volume level and gain setting (this is just another check on the scope calibration)? You could also put the scope in DC mode and use it measure a nominal 1.5V battery? How close is it to what a DVM says? However, IIRC you did measure your filter output but didn't say what the input source was. Was that enough to double check scope vertical cal?
If you hook up the dac output to your preamp/amplifier does it play at a normal volume level and gain setting (this is just another check on the scope calibration)? You could also put the scope in DC mode and use it measure a nominal 1.5V battery? How close is it to what a DVM says? However, IIRC you did measure your filter output but didn't say what the input source was. Was that enough to double check scope vertical cal?
