adamdea
You are not a sound quality evaluation device
Isn't the original concept behind HQP more to do with replacing the dac's DS modulator and doing the whole thing in software (up to dsd), and applying a proper filter right the way up to the modulator rate then transmitting dsd 256 or 512 or 1024 to the dac?I can speak for myself only and I find that using HQPlayer improves sound (I've tried software DSP with a handful of DACs, some in NOS mode).
It also improves measured performance.
I seem to remember that Miska's point was largely that most dacs only use zero order or first order hold filters to go from the upsampled rate (say 384Khz) up to the modulator rate (maybe 11 Mhz or more) and, rather than worrying about the dac's upsampling to 384Khz as such, he was worried about the largely unattenuated images around multiples of 192 Khz which will be left howoever good the firsrt upsampling stage is, .
But I appreciate that HQP will also work more like an mscaler upsampling within multibit pcm and not worrying about the DS stage. Apart from competing with the mscaler this make it useful for dacs which wont take a dsd (256, 512 etc) input.