HQPlayer Embedded Discussion

After following the thread for some time, I noticed that most people here use DSD 512 upsampling on HQPlayer.
Is this because DSD is mathematically simpler and leads to better sound quality?
Or perhaps many DACs have an advantage in DSD conversion.
Maybe both.

Let me know what you think.
I’ll get my first DSD-compatible DAC next month.

A while back this was discussed here:

It’s not an entirely simple answer but most here have come to the conclusion that conversion from digital bits to analog is better done when these digital bits are DSD. The author / developer of HQPlayer also shares this conclusion. But, as you read through the discussion above, it’s not as simple as PCM vs DSD. And, most DACs are specifically designed to handle PCM even converting an input DSD format to PCM for conversion. Then there are specific designs that are 2 DACs in one where DSD is converted through specific DSD circuitry.

It’s a deep rabbit hole. What DAC are you getting? We can tell you a bit about its DSD processing if you like. I say “if you like” because it can quickly become one of those things where the less you know the better off you may be (especially if you already bought it) :wink:

As far as the specific rate of DSD512… Processing PCM to DSD512 can be a fairly intensive CPU heavy operation. Going beyond DSD512 takes a lot of resources most people don’t have access to (me included). Most “DSD DACs” have a sweet spot in their accuracy at DSD256 or DSD512 which is why you see these 2 rates thrown around a lot. It’s a lot easier, if starting with PCM, to get to 705.6/768 PCM. So, if unable to reach the sweet spot of DSD, sometimes staying with a higher PCM rate is preferred. But, again, this is all dependent on DAC and access to a machine to run HQPlayer on. HQPlayer is probably the best tool we have to improve sound quality. It’s at least the most feature rich and configurable. Some of us, like myself, have built their entire playback chain around it even making a DAC purchasing decision based on my use of HQPlayer.

Hope that helps.

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Most DACs have off-the-shelf delta-sigma chips. PCM files are oversampled into the megahertz range so that a bitstream can be generated before the actual " digital to analog conversion ".

Let’s look at the block diagram of the AK4493SEQ chip. Marked in red, PCM (simplified) goes from the internal DSP (DATT / Soft Mute) via the interpolator to the delta-sigma modulator, which again generates the bitstream.

If DSD (marked in blue) is operated in bypass, then DSD is passed untouched by the DSP past the interpolator and modulator. This is a good thing because the external bitstream comes through without further processing and the DAC only does the actual digital to analog conversion. Whether this is the case, however, depends on the overall DAC design.


Source:AK4493SEQ | Audio D/A Converters | Audio Components | Products | Asahi Kasei Microdevices (AKM)

DAC chips are not even remotely comparable to what an audio PC can do in terms of accuracy and quality. DACs typically perform fixed-point calculations with 32 bits or even just 24 bits. The HQPlayer calculates with at least 64 bits, sometimes with 80 bits in floating-point precision.

Higher computing power allows a much higher number of arithmetic operations to be performed during the limited time between 2 output samples (1/target_fs). Pure computing power therefore makes it possible to achieve results with higher precision, since the algorithms used are not so limited by the number and complexity of operations. In most cases, upsampling can then be performed in one step. The filter design in HQPlayer is very extensive and of very high quality.

My recommendation for the DAC: it should be able to be operated in NOS (Non Oversampling). Because this should be done beforehand and the DAC can concentrate on its actual task: the conversion to analog! This way you get the best out of the HQPlayer.

If you want to read more: How to improve the sound of your DAC with an audio PC

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Thank you for your insight.
I will get a Holo Audio May DAC KTE because of its incredibly high reputation here and in other reviews. The introduction of the Holo Audio RED streamer last year was also a game changer, and it was natural for me to consider the brand’s DAC.
I know I’m several years behind most others here, but I hope I made a good choice.
Let me know what you think of the May DAC. :wink:

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Thanks for your insight, too!
I am planning to build another computer for HQPlayer later this year. (Things are pushed back a bit due to budget constraints caused by spending on my other hobby.)
My previous DAC was Accuphase DG-68, and its input was limited to PCM 192/24, so the May DAC I get next month will be quite a leap forward regarding high sampling conversion by the HQP.

I only use a small fanless computer (Skynew K9) for now.
I plan on installing Core i9-14900K based on Jussi’s recommendation, with Seasonic PRIME TX-1300 PSE, but other than those, I haven’t decided much. I will use a large and silence-oriented case, such as Fractal Design Define 7 or Siomi’s AX2, though.

Let me know if you have other suggestions. :wink:

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MAY is a formidable DAC. I always kept saying MAY+HQP is a marriage made in heaven. With HQPlayer already the PCM 1,4/1,5MHz (that requires less computing then DSD) or DSD256x48 with DAC Correction feature “ON” is phenomenal for starters.

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I do like to point out that while sky is the limit if you want to do dsd1024 or 512 with super modulator and dac correction, it really does not take much to get running with hqplayer.

My rpi5 running hqplayer desktop (embedded will be even more efficient) is capable to run dsd256 (native or dop) with 7EC light or dsd512x44 with non EC modulators, default filters and 2s filters with audiolense convolution. Still can’t run super modulator or of course dac correction. Here I am testing the setup with the Signalyst hqplayer DSC2 dac to my Dayton audio tube amp in my home office setup…


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Pi5 still has WAY more processing power than a DAC chip and thus can do way more. Likely also things like simpler headphone or room correction, etc along with the upsampling. Depending on how tight upsampling settings are.

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Does anyone else has the problem that the lincense dongle won’t get accepted anymore after 5.10.1?
With 5.10.0. everything works fine!

Hi Jussi

Can you remind me what is the difference between “amd” and “intel_amd64” hplayerd builds ?

Wish came true very fast :dash:

Thanks @jussi_laako

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My license dongle is working with 5.10.1

Both sides of the May are great. It’s one of the “2 days in one” I mentioned in my previous post as it has separate PCM architecture / circuitry and DSD architecture / circuitry. Worth listening to both sides for sure.

I’m not guru in PC building but do remember that, while playing music, your core utilization is consistent. This can mean moving a lot of heat efficiently off the CPU. The problem with passive cooling is that, once the passive cooler is saturated, you can’t move any more heat. This leads to thermal throttling. Will you saturate your passive cooling solution? Don’t know. It really depends on how heavily loaded your configuration is. Just something to be aware of.

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I see. I’ll try both.
The popular modulator on HQP seems to be “ASDM7EC-super 512+fs,” and I intend to try this one, if not so soon (due to the limitations on computation power).
As for cooling the CPU, I plan to use either a liquid cooler or Noctua NH-D15 G2.
I’ll see how it goes once I’m ready.

I got a May KTE to replace my venerable Spring 1 (Level 2) about three months ago. Best thing I ever did and should have done it years ago. Am enjoying listening to it every day.

I run the AMSDM7EC 512+ modulator at DSD 512 which is an older hybrid semi multi bit design. I find that in my system it gives a fuller sound which I prefer. It is not as intensive as the v3 or Super EC filters so I can also run DAC correction. I use sinc-MGa for 1x and poly-sinc-gauss-hires-lp for Nx.

Running HQP Embedded and Roon Server in Ubuntu Noble Numbat on a music server with an i9-13900KF and RTX 3060. Raspberry Pi NAA to the May.

The server cooling is an AIO CPU with 6 fans in push-pull as an input. The case has 2 further input fans and 4 output fans. Two fans in GPU, one in PSU and one small one in the CPU AIO mount for the voltage regulators. So 16 fans in all, which is why the server is in another room.

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Would love to measure a May ! Would expect super results.

To my surprise, I got my May DAC delivered today.
I’ll set it up over the weekend, but I’ll have to use lower fs / lighter filters for some time.
But first things first.
I’m glad I got one of the best DACs in my hands. :slight_smile:

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I have had my burly new server with i9-14900KS and RTX 4070 TI Super OC since Wednesday, Ubuntu Server 24.04 with NVIDIA drivers. Now I just need a license transfer from my old server. I emailed support@signalyst.com with the relevant information on Wednesday. Am I missing something?

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You have probably got an answer, so please check your junk email folder. In particular if you are using GMail, since it is not at all unusual for our responses ending up there, despite the fact that we never send spam (or any mass email).

Thanks, sorry for the false alarm! You were right, it was caught in spam, likely because it came from a different sender at Signalyst, not as a reply to my original support message.

Update: Config transferred from old server, up and running, GPU working away, hoping to take some time this weekend to try different options that my old server could not handle.

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