Because HQ Player is installed on my server, thought I’d give the demo version a go. After a bit of a phaff, got it working and tried the million tap filter with 15th order linear noise shaping thing . Haven’t got a clue what that means, but a bit of research had suggested it was a good combo. It certainly upsampled the stream as can be seen.
My Prestige is running Roon, HQP Server and NAA. As I understand it Roon hands over all the signal processing to HQP, and HQP outputs an upscaled PCM stream to my DAC. When I go into the HQP settings I see my DAC connected to it.
I use HQP with Roon nowadays. It upsamples the signal going to my Holo Spring 3 DAC, which is a NOS DAC so it greatly benefits when the signal is upsampled. The difference in sound quality compared to upsampling done with Roon native DSP is very clear. There’s a ridiculous amount of possible setting configurations (which all sound different) to try but I’ve been using the ones recommended by HQP developer Jussi Laako. ASDM7ECv2 modulator, poly-sinc-gauss-long filter and DSD256 upsampling. Sounds superb.
But yes the difference HQP does depends on what the DAC does after it receives the signal. NOS DAC obviously does nothing so the HQP upsampling is everything that happens. Most DACs do some kind of upsampling of their own so no matter what happens in HQP, DAC makes its signal processing after that.
Also remember to check if your DAC supports DSDx48 and how many bits it supports.
My Roon core and HQP Server are on Lenovo ThinkCentre m70q mini pc running in a different room. I stream over local network to living room where iFi Zen Stream works as a HQPlayer (NAA) bridge which outputs USB to the Holo DAC. Zen Stream supports up to PCM384 or DSD256.
I was unable to get DSD output, other than white noise, probably if I persevered I could find a setting that got it working, but as the PCM processing made no difference I suspect my DAC is doing its own thing with what it receives which renders external upscaling unnecessary.
Anyway, it sounds awesome as it is, and I was only trying to satisfy my own curiosity which I have now done.
The Chinese seem to be leading the way for affordable, great sounding DACs at the moment.