I just upgraded from my NUC to a dedicated PC for HQPlayer. Despite the significant spec upgrade, I’m running into stuttering even on relatively basic settings. So I suspect that I made some mistakes in the setup or in the config.
Fixed it - turned out to be a LAN issue. Now it plays DSD512 with ext3 and ASDMECv3 + DAC Correction and sounds amazing.
New issue: when I switch to DSD1024, even with lighter filters and modulators, I am getting slowed down and extremely distorted/screechy playback. Since the above works without any stutters, I can’t imagine it’s purely a performance issue.
Have you tried turning off DAC Correction? That is what I had to do to play DSD1024 on a similar setup to yours. What modulator and filters did you try?
Thank you all! Will try without DAC correction and with PCM 1.536 later today.
Custom kernel: I have seen mentions of it but no official link to download it. Could someone point me in the right direction? I’m on Ubuntu Server 24.04 LTS.
It is same place where you already got for example libgmpris. On my personal server where I keep open source parts not necessarily directly related to HQPlayer.
I recommend getting started with the 6.6.x series, it is more tried and tested. You need both the “image” and “headers” packages with matching version. When you install these together, it will also automatically trigger build of the Nvidia driver for this kernel.
“uname -a” shows you are actually running that kernel?
OK, sorry, my bad. If you are using a NAA, this kernel thing needs to be at the NAA side. That’s where the DAC communication happens. It is not relevant to the HQPlayer server side in that case.
Switching back to NAA OS on the RPi fixed the slowdown issue, it now plays at normal speed. Extreme distortion (sounding like a bitcrusher effect) is still there. When pausing playback, very loud white noise plays.
Other conditions tested:
Rate limit 45M and 49M
DAC correction on and off
Simpler filters and modulators (poly-sinc-gauss-long, DSD7)
DoP enabled/disabled, 48k enabled/disabled
FLAC 44.1 and 48 from Tidal
uname-a output:
tr@audio2u:~$ uname -a
Linux audio2u 6.6.87-jl+ #3 SMP PREEMPT_DYNAMIC Sat Apr 19 22:50:42 EEST 2025 x86_64 x86_64 x86_64 GNU/Linux
In case it’s relevant, my USB cable is a basic Monoprice 3ft: Monoprice USB-A Male to USB-B Male 2.0 Cable - 28/24AWG. Also tried with another generic USB A-B cable.
One more variable:
My Holo May is very hot. I had read somewhere to leave it on nonstop for ideal performance. Please let me know if that is not the right advice / could contribute to the issue I’m hearing.
I notice this with mine too, but only sometimes… not always. I’m still trying to figure this out, but I haven’t figured out if there is a rhyme or reason to this.
Right now it’s not too bad… there is a couple of hot spots on the sides that are ~38c. (It is usually a lot warmer, I haven’t used it today so it’s been idle)
The power supply is ~31c.
I have a Serene preamp next to them that is ~30-31c
The DAC seems to run a lot warmer than the power supply. I have the DAC on top of the power supply. Ideally I’d like to separate them but I don’t have the space with the current setup.
The May consumes 60w just sitting when the green light is on. Funny thing, the McIntosh MC462 uses less power at idle than the Holo May! Sometimes if I’m not going to be using the May for a while I turn it off from the front power button. That puts it in standby, the power led will go from green to red.
Cold Holo May (left off overnight) shows the same issue, so temperature is ruled out as a cause.
Mac directly connected to Holo May via USB (incl. USB C-A dongle) w/ HQPlayer Desktop. Local WAV file 44.1kHz. Despite setting it to DSD1024 (and once even to DSD2048), the May’s display only shows 768X. Plays without distortion though.
Curious if the above Desktop observation can give us any indication towards the root cause of the distortion in DSD1024, in addition to the conditions I shared in post #11.
Not sure if this is relevant … but I have an issue whereby I need to hit the “Apply” box in HQP Embedded moire than once in order to get things to run reliably at DSD1024 and PCM 1.4Mhz (1.5… just doesn’t work for me.) So, “Play something, find it’s stuttering or distorted, stop playing, hit Apply again and see if it works. If not, repeat above!”
Sonictransport i9, OpticalRendu, Holo May (with updated USB card.)
I’m using a Raspberry Pi 4 with 8GB RAM as part of the Canakit basic kit (contained a Canakit USB-C power adapter with inline on/off switch).
Description of the power adapter: * CanaKit 3.5A USB-C Power Supply with Noise Filter (UL Listed) specially designed for the Raspberry Pi 4 (5-foot cable)
I don’t think you are going to get DSD1024 easily with ASDM7ECv3. I recommend to try one of the newer modulators that recently got some more optimizations, IOW, ASDM7EC-ul/light/fast/super. The -fast or -fast 512xfs is the recommendation.
ext3 is roughly equally heavy to gauss-xl(a). So I would recommend to get started with the current default 1x=poly-sinc-gauss-long Nx=poly-sinc-gauss-hires-lp and then if you want, change it from there.
But with these you have some known performance baseline.
I also tried with poly-sinc-long and DSD7, had the same distortion issue. Those should work with 1024 on a 14900KF + RTX5070Ti server, right?
Will try the exact settings you suggested tonight and will report back.
Could the third-party (Canakit) power adapter for my RPi have any impact on this? Not seeing the official one for the 4 available anytime soon, but will keep an eye out.
If you have a HDMI monitor attached, watch out for a lightning symbol flashing at top right corner of the screen. If it does, you know you are hitting power limits (voltage drops detected by RPi). But other than maybe some potential ground current issues, I don’t think it would be likely source of issues.
Just the usual reminder to check that your network infrastructure supports 802.3x (Flow Control aka Pause Frames) and that it is enabled.
