I tried HQPlayer a few times as I used to be quite active on the Audiophile Style forums. I remember the original upsampling sounding worse than the Mojo to start with. I mentioned it on the forum. And then the software got upgraded. But it was still clearly inferior to DAVE to my ears. On the other hand, I haven’t tried its latest version.
My take is that the programmer for HQplayer actually has a very different philosophy than Rob Watts. I think HQPlayer doesn’t believe there is an optimal upsampling filter but does believe that a more computationally intense filter and noise shaper is generally better. However, because the software is limited by the GPU and CPU and the memory bandwidrh of the user, my strong suspicion is that the filters in HQPlayer is still very different than the one Rob Watts uses. As a result, I think the HQPlayer upsampling while it might approximate the DAVE filter, it is still an approximation, and hence probably deviates from the sinc filter significantly from DAVE and M-Scaler. Although the HQPlayer programmer insists multiple times that it isn’t true, he also wouldn’t reveal the algorithm he uses.
That said, I think if people prefer HQPlayer upsampling, and/or noise shaping, I’d say good for them. but I wouldn’t equate HQPlayer to M-Scaler as they are probably quite different.
As for the RFI, since many users don’t have the same experience, I think it is equally legitimate to say that it is computer audio induced RFI rather than M-Scaler induced RFI. Ultimately, it comes down to system synergy. I have to admit I would switch my computer audio setup in your shoes (or even just switch to Toslink into M-Scaler). But selling the M-Scaler would save lots of money.
