Does anyone use HQplayer with Rockna WaveDream Reference DAC? I’m wondering what to set for DAC bits when upsampling with HQP and also when not upsampling?
Given Rockna’s guide says that its dither should be used only when listening to 16 or lower bitrate source in NOS mode, I’m curious why would I put anything lower than 24 bits in the HQplayer DAC bits setting?
Because it is technically impossible to create a ladder that would be accurate to 24 bits.
So instead we just use the mostly linear region of the ladder and use noise-shaping dither at high sampling rate to linearize the ladder further and increase audio band SNR beyond 24 bit level.
Sending too many bits to the DAC, in particular without high rate noise shaping dither, results in distorted low level signals. In addition, without dither there is quantization distortion in the output, because the available integer output values don’t exactly match the sample’s real accurate value.
Sending couple of bits less than you properly could use, makes no harm.
1 Like
Thanks Jussi, I set it to 20 DAC bits when upsampling PCM to x8 (I2S maximum) with NS5 dithering.
When I don’t want HQP to do any upsampling before Rockna, I’m guessing 24 bits is fine with TPDF dither on?
Well, I would still keep the bits set to same value. You get less distortion that way.
1 Like
Thanks Jussi.
I’m doing PCM x8 upsampling (I2S max) and dithering with poly-sinc-ext2-xla and NS5 and it sounds great.
But I’m also using Rockna’s Linear filter for the final internal upsample to x16.
In this setup 24 DAC bits setting sounds more alive than anything less than that. When using less bits, it seems like I’m losing on dynamics very much.
Do you know why that might be? Thanks!
I used 18 PCM bits when I demoed Wavedream Reference. That’s measured to be the correct number for Wavelight and I’m pretty sure WDR isn’t performing worse than that.
I also found LNS15 to be the best dither setting. I tried NS5 and TPDF also.
Could you tell me what was your system, Hqplayer settings and Rockna settings when you demoed Reference? Thanks.
My setup is Roon and HQP servers running on a custom built PC running Atlas OS over Windows 11 Pro. I had WDR connected with its LAN connection to LHY AS6 switch, with Blue Jeans Cable Cat6a ethernet. WDR was directly connected to ATC SCM50ASL active speakers with Oyaide Tunami Terzo XLR cables. I used WDR’s own volume control.
HQP was upsampling to PCM 705-768khz (which is WDR’s internal upsampling rate), WDR was in NOS mode obviously when used with HQP. Filter was poly-sinc-hb-l, dither LNS15 and PCM bits 18.
1 Like
Thanks.
First of all, I love your ATCs. 
I believe by using the Reference volume control you’re compromising on the dynamic range, so it might work for you with less bits.
Try it with 0dB and you’ll see its true potential.
Also the difference is you used x16 upsampling which I’m sure is better than my x8 over I2S. My plan is to test it over USB as well.
Anyways, thanks for sharing your experience. 
WDR is so expensive that if I was to keep it, I would’ve sold my Mola Mola Makua preamp and T+A DAC200. That’s why I tested it with direct connection. A device worth ~17ke should have a proper volume control which doesn’t compromise the sound quality. And yes, ATC’s are great 
1 Like
I thought the T+A dac200 already has a great preamp built-in?
Anyway, for me the solution is the benchmark la4 that is relatively inexpensive for multiple inputs.
I hear you. It is expensive but it is the best DAC I’ve heard and I had a few of the big players on test.
It’s the one thing I’m not changing! And not even hqplayer can improve on its sound that easy.
Regarding the preamp comment, even dCS cannot avoid digital volume control compromise. When you get into this DAC category, ignore the volume control that has been added for convenience. You need a preamp.
Enjoy your ATCs, they are great speakers. 
1 Like
Yes it has an analogue preamp built-in, but it doesn’t compete with something like Mola Mola Makua. There’s better control, PRaT, more punch, authority and more dynamic sound with Makua.
WDR is very good, definitely one of the best if not the best DAC I’ve heard. Maybe some day in my setup, but not for now. DAC200 holds its own surprisingly well, especially with the help of HQP. Both, Wavelight and Wavedream Reference, clearly benefit of HQP IMO.
There are proper volume controls built-in to DACs. Relay based analouge volume controls tend to be better. Grimm MU2 sounded stunning on its own, I didn’t miss preamp with it. WDR sounded really good also without a separate preamp. But yes, something like Makua does add great things to the mix.
That’s where hqplayer again comes into play. Digital volume with hqplayer is insanely good, I used to just directly connect dac to power amp and use hqplayer digital volume only and there would be no loss in dynamics I could notice
1 Like
Weird, it doesn’t really affect dynamics. It affects SNR, but you can always test this by setting HQPlayer to pause (with quick pause disabled). It will play silence through the entire DSP pipeline. If you don’t hear background hiss, the number of bits is not limiting you.
With 18 bits and noise-shaping you have more audio band SNR than 24-bit and TPDF. Not that any hardware would have 24-bit worth of SNR anyway (not physically possible). But distortion is lower with 18 bits…
1 Like
Yes, it has a very good relay switched resistor ladder attenuator, like HA 200 too. And the predecessor DAC8 DSD.
These days “preamp” as a term is a bit missleading, since none of the devices are amplifying, instead they are attenuating. So correct term would be “preatt”.
Main issue is that you have let’s day 2V maximum output from the DAC. Then you set “preatt” to -40 dB volume. This results in 20 mV signal going to the power amp. Which then applies for example typical 36 dB of gain, bringing the output voltage to 1.3V that then goes to the loudspeakers…
So shuffling the analog voltage back and forth is rather counterproductive…
So it is better to lower the level from HQPlayer already before it goes out of the DAC, so that you need to attenuate less in analog domain before going out to the power amp. This is what I’d call gain optimization.
1 Like
Here’s my case
In hqplayer, I always set digital volume fixed wt -3db plus in matrix -7db preamp gain hence my digital volume is fixed at -10db which is the optimal digital volume with lower noise/distortion. for my dsc3 dac.
My dsc3 with passive transformer output sends a weaker voltage of 1.5v to my benchmark LA4 preamp
My nuprime evolution sta power amp is low gain at about 21db, together with a weaker dac voltage output, set at -10db in hqplayer. My preamp volume for normal listening level is always around -6 to -10db. So not much loss in dynamics
1 Like
I have HQP set to fixed output (greyed) which is around -6dB. This is enough with my VBA DSP filters so that there’s no clipping.
Makua volume control directly adjusts the output gain. It’s about as good as volume control can get. Low level listening especially is very good with Makua, all the dynamics and detail is there.
1 Like
I’ll check this, thanks. So I just use HQP pause to test the hiss?
Interesting, I never thought about that. I always relied on analogue volume control.