So… The bottom line…
1. HQPlayer provides a nice collection of resampling digital filters to choose from. They work without overloading and suppress ultrasonic artifacts very well. It looks like HQPlayer does this by providing a bit of attenuation for the headroom, this is likely why if we compare the computed RightMark results, you’ll tend to see that the noise level appears higher and dynamic range lower with HQPlayer than JRiver 24 PCM-to-DSD measurements by about 3dB.
These filters would be a great complement if you’re running NOS DACs that can accept high samperate material, and the dithering algorithms provide many options for those who are still using 16-bit DACs. However, if your DAC already provides good filtering and you have no special needs around dithering, it’s unlikely you will hear any additional benefit unless of course you prefer to upsample PCM to DSD with the modulators provided.
2. HQPlayer needs quite a bit of horsepower if you’re planning to do realtime PCM-to-DSD/SDM conversion ; especially if you intend to aim for DSD256+. Your CPU also needs to have SSE4.2 instructions for the 64-bit version (should be fine with any reasonably fast CPU in the last decade). As I did in this post, you can offload some of the calculations to a nVidia GPU with CUDA. The caveat with this is that powerful computers and graphics cards are not fanless currently (and I don’t like the sound of computer fans in my sound room). One should then put the server in another room and stream through a high bandwidth gigabit ethernet system to a NAA (Network Audio Adapter) streamer.
3. F rom a sound quality perspective, I don’t think you could go wrong with any of the “sinc” resamplers and DSD modulators I tested out. While I remain agnostic around which DSD/sigma-delta modulator is “best”, I accept that people can have subjective opinions on this since there are real differences in distortion and noise levels between the different settings. Perhaps certain settings could lead to more “euphonic” output depending on one’s gear. But I believe sonic differences would be at best subtle though based on my own listening and what the results tell me.
4. Notice again, like the last time I measured the Oppo UDP-205 DSD playback, noise floor level increases particularly with the jump from DSD128 to DSD256 and goes back down a bit with DSD512. I suspect there is a good explanation for this. I have not tried measuring my other DSD256+ capable gear at this point to compare how non-ESS DACsperform.
5. The GUI works but is rather spartan compared to many player software out there. This is why historically HQPlayer is used in conjunction with software like Roon for the user interface and library functions. Consider this into the complete system price when incorporating HQPlayer.
Another issue I had was that the program seems to buffer whole tracks or at least large proportions of tracks then begin the conversion before playback. This is fine for PCM upsampling but when doing DSD256 or DSD512 conversion, it can take many seconds to start playback. This wears on one’s patience especially when it can take >10 seconds to start playback even with an overclocked >4GHz quad-core i7 processor with GPU assist. I know there are audiophiles who think buffering to RAM makes a big difference… But surely not when latency can be this severe, right?
6. Have fun with the demo and see if it meets your needs. It is a nice way to experiment on upsampling, trying different filter settings and listen to realtime PCM-to-DSD conversion with a 30-day trial. It’s good to have the experience as an audiophile.