An exploration of Chord DAVE, MScaler, Qutest, and Holo May, HQPlayer

[sajunky]

pi2aes is a sort of a poorman DDC. When adding extras like display, LPS etc... a price is raising close to a full featured DDC. A main job is actually redirecting ground lopps. For a low price $56 you can try Douk Audio U2 Pro, there is a dedicated thread here. Try it with external power supply - even USB phone charger. If it works it means that you need such type of device, get a quality LPS rated 5V/1A. It is not difficult to upgrade U2 Pro with ultra low noise oscilators at a cost below $30 DIY.

 

[GoldenSound]

pi2aes is a sort of a poorman DDC

No it isn't.
It's an excellent piece of kit and demonstrably performs very well at an affordable price.

You do not need a display. Most DDC's do not have a display and there's little reason for them to have one.
The cost of an additional power supply does not change depending on what device you're using. A $300 LPS for a pi2aes costs $300. A $300 LPS for a Lumin U1 Mini or something also costs $300.

A main job is actually redirecting ground lopps

'redirecting ground loops' is not a thing....

 

[GoldenSound]

This statement just confirms that you have the same immagination about ground loops as Amir.. He actually presented his opinion in comments to the TotalDAC Six test, you didn't do yet....

A ground loop is NOT the same thing as noise
Filtering noise be it on the 5v/power OR the ground lines is a completely different task to eliminating a ground loop.
https://www.techhive.com/article/30...noises-from-your-audio-and-video-systems.html

As to Amir, I'm not sure what he has to do with this, and I have no idea what particular comment you're referring to. It would be helpful if you could link it as it's not particularly feasible for me and anyone reading to trudge through the 90 pages of the totaldac thread to try to find what you might be referring to.

Why you don't explain in details what such device is for, if not redirecting ground loops (protecting DAC from a noise coming out from a source)?

There are three main purposes.

1) Provide a very low jitter digital source. AES/SPDIF/I2S are synchronous protocols and so the jitter of the source device directly impacts the DAC itself as the source device is the master clock. Devices may have something such as a PLL to attempt to address jitter from the source but these have limited effect.

2) Reduce noise as much as possible. You are correct that they should reduce the noise on the connection to the DAC, but are incorrect that this is about ground loops.

3) Functional conversion. Sometimes irrespective of quality, you simply need to convert from one digital protocol to another in order to actually connect something. A device may not have a USB input for example.

Now, there ARE some design elements that will eliminate ground loops, some DDC's may offer full galvanic isolation. (And some devices are just for galvanic isolation specifically, such as the Intona 7055-C) But this is not the 'main' purpose and most DDCs will provide exceptionally low noise without galvanic isolation. Because again, a ground loop and noise generally are NOT the same thing.

If you'd like to have a look at the performance of a few digital sources, both jitter and noise, you can do so here:

https://goldensound.audio/2021/08/28/rockna-wavedream-net-review-and-measurements/
https://goldensound.audio/2021/08/1...d-with-sotm-sclk-ex-clock-board-measurements/
https://goldensound.audio/2021/08/01/singxer-su6-measurements/
https://goldensound.audio/2021/07/22/audio-gd-di20he-measurements/
https://goldensound.audio/2021/07/22/pi2aes-streamer-measurements-and-5v-psu-mod-instructions/
https://goldensound.audio/2021/07/22/ifi-zen-stream-measurements/

 

[sajunky]

A ground loop is NOT the same thing as ground noise/ground plane pollution.

You say ground plane polution is different, right, but it spreads inside in EMI form and contribute to the added ground loop on all other wires (not only a ground wire) of the interconnected devices.

There are three main purposes.

1) Provide a very low jitter digital source. AES/SPDIF/I2S are synchronous protocols and so the jitter of the source device directly impacts the DAC itself as the source device is the master clock. Devices may have something such as a PLL to attempt to address jitter from the source but these have limited effect.

2) Reduce noise as much as possible. You are correct that they should reduce the noise on the connection to the DAC, but are incorrect that this is about ground loops.

3) Functional conversion. Sometimes irrespective of quality, you simply need to convert from one digital protocol to another in order to actually connect something. A device may not have a USB input for example.

Now, there ARE some design elements that will eliminate ground loops, some DDC's may offer full galvanic isolation. But this is not the 'main' purpose and most DDCs will provide exceptionally low noise without galvanic isolation.

Most of recent DACs have fully functioning USB port. Just mention few popular DACs, look at Denafrips, Audio GD, new versions of Schiit, Musician or Holo. What noise (mentioned in #2) do you have with asynchronous USB transfers other than ground loops? Come on, look at reality. These DAC's receive bit-perfect feed synchronised with precision internal clocks. We do USB conversion to other formats on DDC (#1), but it is not meant for conversion as current DAC have great performing USB port. So why we still need DDC?

#3 is not a typical use these days.

 

[GoldenSound]

Most of recent DACs have fully functioning USB port. Just mention few popular DACs, look at Denafrips, Audio GD, new versions of Schiit, Musician or Holo. What noise (mentioned in #2) do you have with asynchronous USB transfers other than ground loops? Come on, look at reality. These DAC's receive bit-perfect feed synchronised with precision internal clocks. We do USB conversion to other formats on DDC (#1), but it is not meant for conversion as current DAC have great performing USB port. So why we still need DDC?

The USB implementations in dacs will have varying degrees of susceptibility to noise, and to ground loops.
Whether noise itself will have any impact on the dac depends entirely on the design of the dac. In some cases it will cause a directly audible noise on the outputs of the device, though most dacs should hopefully have filtering to drastically reduce this (but not eliminate).
Some dacs they might not have issues with an audible noise on the output (particularly if using balanced), but could perhaps have other areas of the product such as VXCO's impacted negatively to some degree.

Most decent dacs will have some filtering and counters to these issues. And some higher end ones will have full galvanic isolation, which would also address ground loops. Denafrips does not, nor does musician. Not sure about AGD.
Schiit uses transformer based galvanic isolation which will address DC issues and ground loops but will still allow some AC noise to pass if present (but can then be filtered out after with usual methods.)
Holo uses full laser diode isolation and additionally isolates the USB connector itself from the chassis so there is no electrical connection between the DAC and USB implementation whatsoever and no noise can pass. It uses a very similar method to the intona isolators.

You say ground plane polution is different, right, but it spreads inside in EMI form and contribute to the added ground loop on all other wires (not only a ground wire) of the interconnected devices.

Ground loops cause excessive noise.
This does not mean noise IS a ground loop

 

[Whazzzup]

so does chord dacs, galvanized HD ports, usb is fantastic. ground loops are rarely a problem for most. I hear europe might have issues with "the mains" but i dunno.

 

[tamahome77]

The Pi2AES is a high end ddc in a poor man's suit.

The Pi2AES is a ddc that offers INSANE value! I've had the Pi2AES for the last 15 months and I could tell you it's a big upgrade from audiophilleo 2 with pure power, schiit EITR, singxer SU-1 and gustard U16.

Pi2AES >> SU-1 = EITR >=U16 >> audiophilleo 2 with pure power. The Pi2AES can be had for 1/5 to 1/2 the price of the rest of the ones I've tried.

 

[sajunky]

The USB implementations in dacs will have varying degrees of susceptibility to noise, and to ground loops.
Whether noise itself will have any impact on the dac depends entirely on the design of the dac. In some cases it will cause a directly audible noise on the outputs of the device, though most dacs should hopefully have filtering to drastically reduce this (but not eliminate).
Some dacs they might not have issues with an audible noise on the output (particularly if using balanced), but could perhaps have other areas of the product such as VXCO's impacted negatively to some degree.

Most decent dacs will have some filtering and counters to these issues. And some higher end ones will have full galvanic isolation, which would also address ground loops. Denafrips does not, nor does musician. Not sure about AGD.
Schiit uses transformer based galvanic isolation which will address DC issues and ground loops but will still allow some AC noise to pass if present (but can then be filtered out after with usual methods.)
Holo uses full laser diode isolation and additionally isolates the USB connector itself from the chassis so there is no electrical connection between the DAC and USB implementation whatsoever and no noise can pass. It uses a very similar method to the intona isolators.

It is interesting how far of-topic your elaborate replies can come. Just wonder what are trying to say? To counter my claim, saying that DDC is not needed anymore? Actually user experience is different. These days more people use PC as a source, DDC's are more beneficial and become more popular. It is despite of these measures you describe.

A highlighted part is very interesting and needs a comment. First things, such solution is only possible when USB receiver do not draw USB bus power. When device use bus power, then such floating shield on the receiving side only brings a negative effect (it helps spreading EMI). Secondly, such connection is technically incorrect. It increase a stress for input buffers ESD protection (increasing possibility of breakdown failure). Do it defeat spreading ground loops? Not really. I am not trolling, it is a fact, I have experienced in person.

A method of leaving shield floating had been used for a while among Chineese manufactures. I have to admit, my early model of Audio GD R2R-11 use this method too. Here is link to a post where I had to defeat floating shield, as it was helping in my configuration. There is user feedback that later Audio GD models do not leave shield floating anymore. I wonder, if Holo Audio is still at a stone age? .LOL.

Even if you don't agree on the fact what is technicaly correct or what is better in practice, this is not a matter that should be brought as an example of technical advantage of Holo Audio. As you do, in the long term it will tarnish your reputation.

 

[GoldenSound]

It is interesting how far of-topic your elaborate replies can come. Just wonder what are trying to say? To counter my claim, saying that DDC is not needed anymore? Actually user experience is different. These days more people use PC as a source, DDC's are more beneficial and become more popular. It is despite of these measures you describe.

A highlighted part is very interesting and needs a comment. First things, such solution is only possible when USB receiver do not draw USB bus power. When device use bus power, then such floating shield on the receiving side only brings a negative effect (it helps spreading EMI). Secondly, such connection is technically incorrect. It increase a stress for input buffers ESD protection (increasing possibility of breakdown failure). Do it defeat spreading ground loops? Not really. I am not trolling, it is a fact, I have experienced in person.

A method of leaving shield floating had been used for a while among Chineese manufactures. I have to admit, my early model of Audio GD R2R-11 use this method too. Here is link to a post where I had to defeat floating shield, as it was helping in my configuration. There is user feedback that later Audio GD models do not leave shield floating anymore. I wonder, if Holo Audio is still at a stone age? .LOL.

Even if you don't agree on the fact what is technicaly correct or what is better in practice, this is not a matter that should be brought as an example of technical advantage of Holo Audio. As you do, in the long term it will tarnish your reputation.

I never said a DDC isn't needed anymore, I said that 'redirecting ground loops' isn't their purpose. Good lord...
I honestly don't have the energy to respond to the rest of what you've said.

The AGD device may have had USB connection issues. Others do not, and galvanic isolation is far from specific to holo

 

[sajunky]

I never said a DDC isn't needed anymore, I said that 'redirecting ground loops' isn't their purpose. Good lord...
I honestly don't have the energy to respond to the rest of what you've said.

So what is a reason for such elaborative reply? A sudden surplus of energy? It didn't bring anything to oppose my claim, but it is tarnishing your reputation. And my claim is (I repeat) that a main purpose of DDC is to defeat ground loops and create clean environment for a most critical piece of equipment where DA conversion takes place.

 

[AxelCloris]

[mod comment] We’ve removed several posts that were going off topic and/or getting too personal from the thread. Please keep the discussion on-topic and only discussing personal first hand experiences with gear. Thanks everyone,

 

[Tubewin]

 

[]eep]

Wow, now the old Spring is already surpassed/obsolete?

I think I made a better investment in my new audio and video cabinet and turntable. A turntable I can understand since that's pure physics. And less heated emotions.

 

[alekc]

Wow, now the old Spring is already surpassed/obsolete?

I think I made a better investment in my new audio and video cabinet and turntable. A turntable I can understand since that's pure physics. And less heated emotions.

Wish it would apply to CD transports too Good, it applies at least in a little bit after all.

 

[ardbeg1975]

Please direct me elsewhere as appropriate. I've been experimenting with HQPlayer and the Qutest and I'm having issues getting to X16 PCM upsampling to the Qutest via USB. I'm running Roon to HQ on an M1 MacBook Pro and I'm getting audio glitches / gaps. I don't have this problem at X8. Running Sync-M and LNS15. CPU looks fine. Don't have this issue with Intel-based Macs. Any guidance? Changing buffer doesn't seem to help. Thank you.