Overthinking DSP & how to build an audiophile PC

jamster

Wammer
Wammer
Dec 30, 2010
438
210
58
Lichfield
AKA
Chris
HiFi Trade?
  1. No
I was a bit taken aback by the measured performance of the TDAI-3400...
I like the look of the TDAI-3400 but I think it is overpriced, personally. I seem to recall that the ASR measurements are measuring analogue input, which is not really how these DSP amps are meant to be used I think. But I could be wrong.
 

jamster

Wammer
Wammer
Dec 30, 2010
438
210
58
Lichfield
AKA
Chris
HiFi Trade?
  1. No
I understand now. I agree that unless he wishes to DSP with HQPlayer they he probably won’t need a dedicated super computer. But I’d like me he thinks that HQP will provide the best performance then he has no alternative but to put together a powerful machine and I see no harm in dealing with EMI/RFI issues.
Got it, that makes sense.I have learned something new: upsampling to DSD, which seems to be the key differentiator here.

Must try it out on my Razer Blade, and see how it compares to the Sabre's IC based filters (which are meant to be some of the best in dedicated silicon).

 
  • Upvote
Reactions: tuga

Heckyman

Wammer
Wammer
Oct 15, 2011
384
137
73
West Yorks
AKA
Andrew
HiFi Trade?
  1. No
Haven't compared it to an audiophile PC, but the new Mac mini is surely worth a try if it runs the software you want to use. Totally different machine to its Intel based predecessors. Sounds great plugged into my hifi block  ;-)  

If you need a super computer for some reason, wait for the new Mac Pros.

 

Phobic

Mildly Annoying
Wammer Plus
Aug 29, 2020
3,450
3,059
0
Worksop
HiFi Trade?
  1. No
thanks I had my wires crossed, it's a DAC!

Most DACs will apply a form of upconversion to the input signal via an off-the-shelf SRC chip or the one embedded in the D/A chip and use the filter or filters bundled with said chip.

HQPlayer only needs the D/A conversion because it performs the upconversion, the filtering and the dithering (and EQ, crossover filtering as well if needed). It does so using far more refined algorithms which require a lot of processing power, much more even than what is available for example in an FPGA-based device like the MScaler.

By removing upconversion and filtering from inside the DAC you are also removing sources of EMI/RFI noise as well as the demands that they impose on the power supply.
that's my prime driver for using HQPlayer, and also as the algorithms are software they can be much easily upgraded in the future.

Also, in most DACs the Redbook PCM signal is upconverted by an off-the-shelf SRC chip and then gets modulated into the D/A stage (is turned to DSD).
DSD signal goes straight into the D/A stage.
Thanks for this, it's something that I'd never considered or looked at, quite a good upside.

if I understand things currently HQplayer will convert PCM to DSD on the fly as well.

I am asking the OP what particular advantage a higher power PC will give over an IC (hifiberry, minidsp etc.). The number of IIR and FIR taps on both is plenty, afaik.

Genuinely interested.
I'm not sold on a PC but it makes a lot of sense, I prefer storing my FLAC files on a PC (I have a NAS but find it too slow), it can be multi-purposed for hifi by also running HQPlayer, and the DSP functions are pretty impressive compared to standalone DSP e.g. with a PC you can easily get 65k taps.

That is why I was asking what the priorities were. With an endless budget the sky is the limit but that is hardly ever the case.
I'm not thinking about budget for this yet, I want to understand what the best solution is and then look at what's right for me in terms of features and priorities. My top priority is sound quality. Then it's more a case of seeing how much it costs, if it's affordable then that's easy :)  if it's not then I'll have to look at options to get the cost down.

But what exactly does he want to do with the PC? For some simple REW filters, a PC is possibly overkill. For anything more advanced, then you either need a lot of skill, or to buy something off the shelf e.g. Dirac.
REW filters are too simplistic, DIRAC looks very good but I think I need more control, I'm a tweaker & power user so a steep learning curve doesn't phase me.

 I agree that unless he wishes to DSP with HQPlayer they he probably won’t need a dedicated super computer. But I’d like me he thinks that HQP will provide the best performance then he has no alternative but to put together a powerful machine and I see no harm in dealing with EMI/RFI issues.
think I've already made my mind up on HQPlayer given the DSP processing in the DAC, I very much like that architecture!

Haven't compared it to an audiophile PC, but the new Mac mini is surely worth a try if it runs the software you want to use. Totally different machine to its Intel based predecessors. Sounds great plugged into my hifi block  ;-)  

If you need a super computer for some reason, wait for the new Mac Pros.
I'm a windows guy I'm afraid.

 

Phobic

Mildly Annoying
Wammer Plus
Aug 29, 2020
3,450
3,059
0
Worksop
HiFi Trade?
  1. No
looks like going down the NUC route is a good answer then, I think that I can make this work with Roon but want to double check.

my existing PC will run Roon Core + HQPlayer server (with DSD conversion) + DSP software (maybe Acourate), I'll produce filters in the DSP software and load them into HQPlayer.

A low CPU power NUC will run HQplayer client connecting back to HQplayer Server over Ethernet (or wifi??) and will output locally over the NUCs USB to the DAC.

I should be able to control the Roon core via any roon client as I do right now.

All sounds perfect.

The only bit I'm unsure about is how to feed multiple Subs in this setup? I'm going to need different filters for each sub, HQPlayer I think supports multi channel, I assume there are DACs which support multiple channels over the USB interface?

EDIT: a quick search and there are

https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-okto-dac8-8ch-dac-amp.7064/

 
Last edited by a moderator:

tuga

. . .
Wammer
Aug 17, 2007
12,547
5,067
173
Oxfordshire, UK
AKA
Ric
HiFi Trade?
  1. No
I'm not thinking about budget for this yet, I want to understand what the best solution is and then look at what's right for me in terms of features and priorities. My top priority is sound quality. Then it's more a case of seeing how much it costs, if it's affordable then that's easy :)  if it's not then I'll have to look at options to get the cost down.
Estelon has at least one active speaker model that I know of which comes with HQPlayer NAA / hardware endpoint:

http://estelon.com/estelon-high-end-show-munich-renewed-flagship-extreme-wireless-speakers-lynx/

I expect this to become a little more widespread in the future.

 

tuga

. . .
Wammer
Aug 17, 2007
12,547
5,067
173
Oxfordshire, UK
AKA
Ric
HiFi Trade?
  1. No
I’ve just noticed that Estelon is using only base-rate DSD64 which is a bit low.

It is likely that this is so because they are doing multichannel and/or cannot get a powerful processor into the speaker cabinet.

 

tuga

. . .
Wammer
Aug 17, 2007
12,547
5,067
173
Oxfordshire, UK
AKA
Ric
HiFi Trade?
  1. No
looks like going down the NUC route is a good answer then, I think that I can make this work with Roon but want to double check.

my existing PC will run Roon Core + HQPlayer server (with DSD conversion) + DSP software (maybe Acourate), I'll produce filters in the DSP software and load them into HQPlayer.

A low CPU power NUC will run HQplayer client connecting back to HQplayer Server over Ethernet (or wifi??) and will output locally over the NUCs USB to the DAC.

I should be able to control the Roon core via any roon client as I do right now.

All sounds perfect.

The only bit I'm unsure about is how to feed multiple Subs in this setup? I'm going to need different filters for each sub, HQPlayer I think supports multi channel, I assume there are DACs which support multiple channels over the USB interface?

EDIT: a quick search and there are

https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-okto-dac8-8ch-dac-amp.7064/
That DAC looks very tempting.

I know that HQPlayer does multichannel but it’s not something I can help you with.

Jussi Laako is active on the Roon forum. I would make myself a member and ask the right questions there.

 
  • Like
Reactions: Phobic

jamster

Wammer
Wammer
Dec 30, 2010
438
210
58
Lichfield
AKA
Chris
HiFi Trade?
  1. No
think I've already made my mind up on HQPlayer given the DSP processing in the DAC, I very much like that architecture!
It looks like a NVIDIA GPU would be a good bet as the software appears to do GPU offload.  Making it silent will be a challenge. :D

 

Phobic

Mildly Annoying
Wammer Plus
Aug 29, 2020
3,450
3,059
0
Worksop
HiFi Trade?
  1. No
It looks like a NVIDIA GPU would be a good bet as the software appears to do GPU offload.  Making it silent will be a challenge. :D
I think HQplayer does client server, hopefully it works like I think it does so the noisy Nvidia card can be in another room. At least that's my plan.