GUSTARD DAC-R26 Balanced Decoder R2R+1Bit Dual Native Decoding Music Bridge

Nov 22, 2022 at 4:37 PM Post #1,756 of 9,972
Happily playing the Gustard R26 over LAN, using Foobar player with Foo_out_upnp.
Foo_out_upnp finds two UPnP endpoint devices for it:
  • UPnP : Gustardrender-1v3
  • DSD : UPnP : Gustardrender-1v3
I've got the latter selected, as the first won't play DSD I think, at least the display will show 176 kHz or so playing DSD64
No buffering issues; it plays DSD256 happily.
When I pull the ethernet cable from the local ethernet switch, it will keep playing music for several seconds !

Got 2x Delock Network Isolators 6 kV RJ45 with 25 cm CAT7 S/FTP cables in series !
But honestly, I haven't heard a difference with or without these :relaxed:
Similarly, haven't noticed burn in effects, and certainly don't trust my auditory memory.
A big buffer is an easy way to test if all the gadgets/switches/LPSUs make any difference. Just pull the Ethernet cable and check if anything changes.
 
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Nov 22, 2022 at 5:37 PM Post #1,757 of 9,972
If anyone is wanting to try the best external clocking for the R26, then arguably the ideal is to use I2S. Not a dedicated external clock. (Apologies to those invested in external clocks).

Using a 10MHz external clock still forces the R26 internal re-clocking to 44.1 or 48kHz family clock rates. This final clocking process can be expected to dominate the clock signal into the R2R ladder itself.

Will be worth it to compare a quality streamer like the RPi with the internal LAN input using Audirvana on Mac, Bubble upnp or Mconnect. Moode Audio is a well proven, well sorted RPi interface which I know delivers the goods.

This is a great plan. Is there a way to tease out any sound changes from the connection factor versus the clocking using I2S?

It seems the R26 ethernet clocking goes via the 10MHz clock (int or ext) to the internal reclocking chip.

The R26 with I2S input seems like it can run on either the I2S clock or the internal clocking via OS vs NOS settings. So with the I2S you can test ethernet vs I2S (OS) to test inputs. Then test the R26 bespoke internal clocking vs the I2S clocking.

The Allo Kali has dedicated clocks for the 44.1 and 48kHz modes with claimed <4ps jitter. Research indicated <10ps jitter is not audible, in even the worse test scenario (puretone at high freq). So this is an ideal test bed for interrogating the internal clocking of the R26.

Can you test blinded? Making a DIY silver I2S cable will render most of us incapable of unbiased listening.

A big buffer is an easy way to test if all the gadgets/switches/LPSUs make any difference. Just pull the Ethernet cable and check if anything changes.
That's brilliant. Especially if prior to pulling the ethernet cable the data is flowing. If the buffer is full and not receiving then any active noise issue will be queiescent. How can you tell if data acquisition is active?
 
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Nov 22, 2022 at 6:10 PM Post #1,758 of 9,972
If anyone is wanting to try the best external clocking for the R26, then arguably the ideal is to use I2S. Not a dedicated external clock. (Apologies to those invested in external clocks).

Using a 10MHz external clock still forces the R26 internal re-clocking to 44.1 or 48kHz family clock rates. This final clocking process can be expected to dominate the clock signal into the R2R ladder itself.



This is a great plan. Is there a way to tease out any sound changes from the connection factor versus the clocking using I2S?

It seems the R26 ethernet clocking goes via the 10MHz clock (int or ext) to the internal reclocking chip.

The R26 with I2S input seems like it can run on either the I2S clock or the internal clocking via OS vs NOS settings. So with the I2S you can test ethernet vs I2S (OS) to test inputs. Then test the R26 bespoke internal clocking vs the I2S clocking.

The Allo Kali has dedicated clocks for the 44.1 and 48kHz modes with claimed <4ps jitter. Research indicated <10ps jitter is not audible, in even the worse test scenario (puretone at high freq). So this is an ideal test bed for interrogating the internal clocking of the R26.

Can you test blinded? Making a DIY silver I2S cable will render most of us incapable of unbiased listening.


That's brilliant. Especially if prior to pulling the ethernet cable the data is flowing. If the buffer is full and not receiving then any active noise issue will be queiescent. How can you tell if data acquisition is active?
Thanks Nada.

Two quick questions on the clock:

- Would you expect any gains with a clock direct to DAC vs not at all?
- Can you confirm what this picture means? I took it to mean that the clock synthesisation feature (which should reduce noise/jitter) only works on USB / LAN, and therefore a clock straight to the DAC when using LAN would be optimal, vs using IIS via a DDC?

I am not that familiar with clocks so I could be all wrong here.
 

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Nov 22, 2022 at 6:30 PM Post #1,759 of 9,972
Two quick questions on the clock:

Im not a clocking expert so I will defer to other members here. There are likely to be some diverse opinions on best clocking. My thoughts which are not evidence based so I urge you to read them with skepticism are:

1. To know what clocking does requires an audio analyzer. The good ones cost over $20k. The measurements of clocking for the R26 are lacking. There are two published both using SPDIF on AES if I remember correctly but not clarifying if they use a proper J-test with toggling of the LSB or if the R26 is set to NOS or OS. This is really unsatisfactory as there's no indicator if the jitter tests even used the 10MHz clock at all.
2. The R26 info suggests with I2S in it will use internal clocking in OS mode and I2S clocking in NOS mode. In other Gustard DACs I2S requires defined clock frequencies for both 44.1 and 48kHz family clock rates. So not all I2S DDC can be expected to work. Info sharing here is important to find DDC'swith the correct clock rates and pin outs.
3. I dont have an audio analyser and all of this speculation is yet to be confirmed
4. However the internal clock and synthesizer of the R26 looks technically superb. There is no apparent reeason to try and improve it but that's what audiophiles just do. For those who want a minimalist setup theres no need to get concerned. Just plug in the lan and enjoy the music :)
 
Nov 22, 2022 at 6:47 PM Post #1,760 of 9,972
I found the iFi iPurifier S/pdif 2 powered by a spare iFi Power X really improved the sound from that super jittery source. It's effectively a DDC which reclocks the signal so the character of improvements is similar to the OCK-1 but on a smaller scale. Etched edges reduce, voices become more full bodied and natural and bass has more impact and a bit of a soundstage. Just sounds much more hifi. Recommended.*

Incidentally the R26's external clock does not apply to s/pdif optical or coax inputs. There is no effect of toggling the OCK-1 on and off.
From memory i believe that the spdif inputs take the clock data from the source. If you have the U18DDC, just as a test, try the OCK-1 output into the u18, and send the spdif signal from there into the R26.
 
Nov 22, 2022 at 8:27 PM Post #1,761 of 9,972
From memory i believe that the spdif inputs take the clock data from the source. If you have the U18DDC, just as a test, try the OCK-1 output into the u18, and send the spdif signal from there into the R26.
I agree the spdif signal carries the clock data from the source and unless the recipient DAC and/or DDC (if used) actively rebuffers and reclocks it (as the iPurifier does, alongside galvanic isolation that's its main function) then the DAC is stuck with that poor quality word clock signal. Which would explain why the iPurifier made such an improvement.

I tried Zen > U18 > R26 via spdif coax just yesterday actually testing whether the external clock was in play with NOS on and off via that input in line with a recent Gustard clarification. From my quick and casual single AB it sounded pretty good actually, better than I was expecting, a little smoother and warmer than i2s if perhaps not as resolving. Clock connected to both U18 & R26.
 
Nov 23, 2022 at 2:24 AM Post #1,762 of 9,972
I agree the spdif signal carries the clock data from the source and unless the recipient DAC and/or DDC (if used) actively rebuffers and reclocks it (as the iPurifier does, alongside galvanic isolation that's its main function) then the DAC is stuck with that poor quality word clock signal. Which would explain why the iPurifier made such an improvement.

I tried Zen > U18 > R26 via spdif coax just yesterday actually testing whether the external clock was in play with NOS on and off via that input in line with a recent Gustard clarification. From my quick and casual single AB it sounded pretty good actually, better than I was expecting, a little smoother and warmer than i2s if perhaps not as resolving. Clock connected to both U18 & R26.
You had the clock connected to both sine wave or 1 square wave / 1 sine wave out? Is it possible output both wave types simultaneously? Or is it better to stick with one over the other? Considering taking the plunge into a clock as I have both a U18 here now and my R26 is supposed to be here this week. Thanks.
 
Nov 23, 2022 at 2:53 AM Post #1,763 of 9,972
You had the clock connected to both sine wave or 1 square wave / 1 sine wave out? Is it possible output both wave types simultaneously? Or is it better to stick with one over the other? Considering taking the plunge into a clock as I have both a U18 here now and my R26 is supposed to be here this week. Thanks.
Hi, yes you can mix and match square and sine. I must’ve had the OCK-1 for around 6 weeks, using square as my primary output ( first the U18, then the R26 when it arrived) because of its theoretical superiority which I accepted at face value such was the improvement the OCK1 made. I also doubted sine vs square would make any difference really. So you can imagine my surprise when I only got around to AB’ing sine vs square last week first time, I found that for the R26 clock input sine was clearly audibly better than the square wave I’d been using for weeks. End result I’ve now got both the U18 & R26 connected to the sine output of the OCK1, using a Gustard C2 cable each. All sounding pretty good, though as you might’ve read I now prefer the R26’s internal streamer acting as a HQplayer NAA point.

Edit - in case droll Kiwi phrases don’t translate well by pretty good I mean terrific.
 
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Nov 23, 2022 at 3:00 AM Post #1,764 of 9,972
Hi, yes you can mix and match square and sine. I must’ve had the OCK-1 for around 6 weeks, using square as my primary output ( first the U18, then the R26 when it arrived) because of its theoretical superiority which I accepted at face value such was the improvement the OCK1 made. I also doubted sine vs square would make any difference really. So you can imagine my surprise when I only got around to AB’ing sine vs square last week first time, I found that for the R26 clock input sine was clearly audibly better than the square wave I’d been using for weeks. End result I’ve now got both the U18 & R26 connected to the sine output of the OCK1, using a Gustard C2 cable each. All sounding pretty good, though as you might’ve read I now prefer the R26’s internal streamer acting as a HQplayer NAA point.

Edit - in case droll Kiwi phrases don’t translate well by pretty good I mean terrific.
Great. Thanks! I am interested in setting up an NAA for streaming to the R26. I have external hard drives and a computer, but to set-up the NAA requires a separate computer to use as a "host" of sorts, right? I currently stream from my HDD [or Qobuz from my phone using MConnect] to the RPi4 w. Pi2AES using Moode into foobar via UPnP.
 
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Nov 23, 2022 at 3:04 AM Post #1,765 of 9,972
Great. Thanks! I am interested in setting up an NAA for streaming to the R26. I have external hard drives and a computer, but to set-up the NAA requires a separate computer to use as a "host" of sorts, right? I currently stream from my HDD [or Qobuz from my phone using MConnect] to the RPi4 w. Pi2AES using Moode into foobar via UPnP.
On that computer you have, you install HQPlayer. Connect to the DAC with a network cable. On the DAC, you select the LAN input. That's all.
 
Nov 23, 2022 at 3:05 AM Post #1,766 of 9,972
Great. Thanks! I am interested in setting up an NAA for streaming to the R26. I have external hard drives and a computer, but to set-up the NAA requires a separate computer to use as a "host" of sorts, right?
In terms of what you prefer YMMV, as many others prefer the U18/R26 combo, but give it a go, see what you think. My setup is Roon + HQplayer installed on a Mac Mini M1 16Gb. No separate host. HQplayer immediately ‘saw’ the R26 as ‘Gustarender’ just as it saw the Ifi Zen Stream as NAA - you just select either one from a drop-down list.
 
Nov 23, 2022 at 3:08 AM Post #1,767 of 9,972
On that computer you have, you install HQPlayer. Connect to the DAC with a network cable. On the DAC, you select the LAN input. That's all.
Any idea how I could get HQPlayer to work with the Pi2AES? I don't see an option for connecting to the RPi4 through HQPlayer. Cheers.
EDIT: BTW, I do plan on comparing USB > U18 >IIS to LAN to RPi4 > AES when the R26 arrives.
 
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Nov 23, 2022 at 3:10 AM Post #1,768 of 9,972
In terms of what you prefer YMMV, as many others prefer the U18/R26 combo, but give it a go, see what you think. My setup is Roon + HQplayer installed on a Mac Mini M1 16Gb. No separate host. HQplayer immediately ‘saw’ the R26 as ‘Gustarender’ just as it saw the Ifi Zen Stream as NAA - you just select either one from a drop-down list.
Any chance you can share any upsampling settings you find are working well please? I have the exact same set up (Mac mini, Gustard via LAN), and just started with HQ player today (eg are you up sampling to PCM or DSD and what filters). I find the sheer range of options on HQ player overwhelming.
 
Nov 23, 2022 at 3:16 AM Post #1,769 of 9,972
Any chance you can share any upsampling settings you find are working well please? I have the exact same set up (Mac mini, Gustard via LAN), and just started with HQ player today (eg are you up sampling to PCM or DSD and what filters). I find the sheer range of options on HQ player overwhelming.
THIS. And before anyone gets snippy, this is absolutely on topic as we are talking about getting HQPlayer working with all DACs, including the R26. lol
 
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