High quality power supplies for single board computers

[nbpf]

With the introduction of transports like the Allo DigiOne and USBridge, single board computers requiring power supplies able to deliver about 3A at 5VDC or less are becoming increasingly popular as stand-alone music server or as S/PDIF and USB network renderers. Some contributors to these forums have argued that improvements in sound quality that can be achieved by powering single board computers with high quality power supplies. What are suitable high quality power supply for single board computers? Has anybody compared UpTone Audio's JS-2, Custom HiFi Cables' DC3, Paul Hynes power supplies, etc. to less expensive wall wart power supplies like the ifi iPower and the Allo 5V/3A? If so, please, report your findings!

[nbpf]

53 minutes ago, tapatrick said:

I recommend Paul Hynes SR4, an excellent PSU for the price which uses much of the technology of his SR7 and I didn't have to wait long for delivery. I have 2 which I use for SBCs.

Thanks tapatrick! Have you noticed any improvements against other PSUs when powering your SBCs with the SR4s?  

[nbpf]

5 hours ago, tapatrick said:

I haven't specifically compared different PSUs running SBCs but I had run dual in series LT3045 voltage regulators after a modified Teradak DC30 and also a LPS1which improved sound significantly. When I got the SR4 I found I did not need the LT3045s afterwards as they did not make any further improvement which convinced me of its quality.

Very nice, thanks for your assessment!

[nbpf]

39 minutes ago, barrows said:

I can make power supplies optimized specifically for these types of loads, with standard leading low noise and output impedance....

Thanks, but the focus here is to compare existing high quality power supplies (JS-2, DC3, etc.) to less expensive wall wart solutions for SBCs.

[nbpf]

42 minutes ago, barrows said:

...

But, I would caution folks to understand that one is never going to get the best performance for audio by using the commercial computer gears suggested here.  Even with an ultra low noise pre-regulated supply, these boards are going to have noisy DC/DC switching regulators onboard, so they are going to make a lot of noise on the board.

Higher performance solutions are available, built for audio purposes, which do not use noisy DC/DC converters.

Good point but I am not aware of currently available S/PDIF server or network renderer solutions that are designed to match or exceed the performance of the DigiOne. If I am overseeing some products, please let me know! Of course, we do have excellent network renderers and, lately, servers with USB outputs. But these devices need to be complemented with USB to S/PDIF interfaces in order to deliver S/PDIF streams. The quality of the results depends then crucially on the quality of the interface and of its power supply! Other major limitations of currently available devices built for audio purposes are their very limited customizability and the lack of certifications for publicly available operating systems: many users would not mind investing in high performance servers built for audio purposes if they knew that, beside running the manufacturer's proprietary OS, these devices can also boot a standard Linux distribution. For users that need S/PDIF outputs and/or some control and customization options, commercial SBCs and dedicated interfaces like the ones mentioned in my original post are, if not optimal, at least viable solutions.

[nbpf]

22 minutes ago, barrows said:

... Additionally, SPDIF basically sucks, but that is another topic...  It is too bad that some DACs do not put a well engineered USB input in their DAC... especially now as the way to do it is fairly well understood.

Agree but ... what can you do? There are some good old DACs that have S/PDIF inputs ...

[nbpf]

25 minutes ago, barrows said:

There are High End Ethernet Renderers which include SPIDF output: Like Bricasti and dCS, and Sonore used to make the Sonore Signature Rendu which is a superb SPDIF source if you can find one on the used market.  Both of these will easily outperform ordinary commercial computer solutions like Allo, etc.

Perhaps yes but I am more interested in solutions that can act as integrated server and renderer. Maybe the new Antipodes CX or the announced Innuos Signature will be interesting devices. For the time being, I have to rely on off-the-shelf headless computers with dedicated Linux distributions and USB to S/PDIF or, better I2S to S/PDIF interfaces. By the way, the DigiOne is actually not bad, as far as I can say. And over at the Naim forums, a few users have been testing DigiOnes to stream Qobuz and Tidal to their NDS streamers and reported good results. It is not an NDS, of course. But it's quite good!     

[nbpf]

13 minutes ago, barrows said:

Agreed, if you must use SPDIF then use one of the Renderers which has a SPDIF output, or use a good USB-SPDIF converter.  The converter, if well designed, offers the additional advantage of another stage of noise isolation (for example the Sonore ultraDigital is isolated between USB receiver section and SPIDF output), and the converter also performs a s a re-clocker.

Yes, I have tried many USB-SPDIF converters, including the Mutec MC-3+ USB and the Schiit Eitr. To tell you the truth, I wa not impressed by the Mutec. I still have an Eitr connected to the RPi that hosts the DigiOne. Thus, I can easily compare the two by just switching inputs on the Naim DAC. The DigiOne also provides galvanic isolation and reclocking. I am not sure that the latter is very important in my case: the old Naim DAC apparently overrides the clocking of the SPDIF stream with its internal clocks before this enters the DSP and DAC stages. Alas, just put a memory slot and a wireless board on the top of the ultraRendu and we do not have to play around with off-the-shelf computers any longer!

[nbpf]

59 minutes ago, barrows said:

I doubt that is the case with your DAC.  Even if it internally resamples the data to the DAC clock, it still has to reconcile the DAC clock with the SPDIF clock.  Typically this is done with a PLL, and these circuits effectively couple the incoming SPDIF jitter to the DAC clock.  This is different form async USB, where the DAC clock can be the true master and does not have to sync with any incoming clock (because async USB is two way, and the rate the data is being sent can be adjusted by the DAC).

 

There are some DACs with fully async SPDIF receivers, but they are very rare.

From https://www.naimaudio.com/sites/default/files/products/downloads/files/naim_dac_august_2009.pdf I understand that PLL is only used to select one of the internal clocks. This is then used to clock the buffered SPDIF data for the DSP and DAC sections. I might be missing something, of course.

 

I also have an old M2Tech hiFace Evo that, if I am not mistaken, uses asynchronous USB. The M2Tech is connected to an headless CompuLab fitPC3 running a minimal Debian system. Both the M2Tech and the fitPC3 are powered by Teddy Pardo LPSUs. This has been my default system for about five years. Now I have the impression that the DigiOne sounds a little bit better than the M2Tech. 

[nbpf]

5 hours ago, barrows said:

Linux is a very flexible computing platform.  Really, the OS used for our (Sonore) products, and most Linux based servers as well, is as you describe: designed from the ground up for audio purposes.

In which sense is Sonicorbiter designed from the ground up for audio purposes? Doesn't it rely on MPD, upmpdcli, alsa-utils just as Volumio, DietPi, etc. do? Basic latency improvements can be achieved by simple OS tuning as documented in https://wiki.linuxaudio.org/wiki/raspberrypi. I am actually not aware of any documented OS that has been designed from the ground up for audio purposes but I might be mistaken, of course. Projects like  http://wtfplay-project.org/index.html#about go quite a long way towards optimization and minimalism but they do not attempt at designing any OS from the ground up, I believe.  

[nbpf]

Back to the topic: has anybody compared UpTone Audio's JS-2, Custom HiFi Cables' DC3, Paul Hynes power supplies, etc. to less expensive wall wart power supplies like the ifi iPower and the Allo 5V/3A for powering SBCs?

[nbpf]

1 hour ago, vortecjr said:

SonicOrbiter is one part closed source and one part open source. The closed source is 100% developed by SGC and Sonore. This part of the OS is the software on top of the software that controls and configures the system. The closed source is Fedora GNU/Linux. We do not develop this part of the operating system, but as can be expected we interact with some of the developers on a regular basis. There is also some third party apps that are closed source that run on the unit. Also SonicOrbiter is meant to be a flexible "system" and it can be configured to act as a music server / NAS or a renderer. These work well independently or concurrently of each other. For the music server we are using off the shelf hardware. For the renderer we are developing our own hardware and the software is highly optimized (in ways I don't care to explain in a public forum) to work with each other. We feel this approach gives us greater flexibility to control the vertical and horizontal.

My post was not meant to be in any way dismissive of the work involved in selecting and integrating existing software components and in providing customization options for those components, e.g., via new and well designed web interfaces. It is just that I do not believe that such developments warrant the outcomes to be denoted as  "designed from the ground up". It is finally only a matter of taste in the way language is used and we can agree to disagree on this point, I believe! Thanks for the clarifications on SonicOrbiter!  

[nbpf]

1 hour ago, vortecjr said:

If by "compare" you mean measure...I have measured various power supplies with our gear. I have our power supply, JS-2, iFi and a few others here. 

Sure, careful comparisons can involve measurements. But they do not have to and I am also very interested in the subjective findings of users who have powered their DigiOne, USBridge, HiFiBerry, etc. devices with high quality power supplies. Have such PSUs brought improvements in sound quality over power supplies like the ifi iPower? Did they have any impact at all?

 

As put forward in the title, I am interested in the impacts of high quality power supplies on SBCs that are deployed (typically as hosts for devices like the Allo DigiOne) as server and/or network renderers. The impacts of high quality power supplies on devices like the ultraRendu, the sMS-200ultra, etc. have been discussed in detail in other threads in this forums. 

[nbpf]

11 minutes ago, vortecjr said:

We can lump these all together and talk in generalities since I don't like to pick on other products. I mostly measure USB to analog and USB to SPDIF devices. The devices I use are powered from the SBC. So the SBC and the converter remain the same and the power supply varies. I can describe what I see if you feel that relates to your question.        

Sure, go ahead. The more we understand the better. Thank for making you expertise available to this discussion!

[nbpf]

2 minutes ago, vortecjr said:

Comparing SPDIF, USB, and a DAC hat with different power supplies would be to complex right out of the gate. I'm most familiar with USB to analog, but I don't feel that the DAC hat will be much different with respect to the results with different power supplies. What are you actually using right now? 

I am using an ifi 5V iPower to power a RPi + DigiOne and Teddy Pardo 12V/4.5A and 9V/2A units to power fitPC3 and M2Tech hiFace Evo, respectively. The Schiit Eitr is powered by its own AC/AC wall wart. I am particularly interested in whether a JS-2, DC3 or SR4 could possibly improve the sound quality of the RPi + DigiOne combo. I understand that the best results would likely be obtained by powering RPi and DigiOne separately, but this is not the focus of this thread. Thanks, nbpf

[nbpf]

3 hours ago, vortecjr said:

There is a simple test you can conduct. iFi Audio sells a device called the Groundhog that allows you to connect the ground of your AC power source  to the negative terminal of the DC output of your iFi iPower supply. Depending on your electrical skills you can also make the cable.    

I am not sure I understand: I have no problems with humming or buzzing components in my system. The only device connected to the amplifier (a SN2) is the Naim DAC and its grounding is set to chassis as per manual. I understand that if I had to connect another grounded device to SN2 I would have to set the grounding on the DAC to floating to avoid ground loops. But the Groundhog seems to address cases in which the grounding is missing (no device in the chain providing a grounding) which is not the case here. Am I missing something? 

[nbpf]

1 hour ago, vortecjr said:

The iFi iPower Supply does not have a ground pin.

 

Have a look at this post for details on what this ground trick does: 

 

Got it! I am going to try it tomorrow, thanks! 

[nbpf]

20 hours ago, vortecjr said:

There is a simple test you can conduct. iFi Audio sells a device called the Groundhog that allows you to connect the ground of your AC power source  to the negative terminal of the DC output of your iFi iPower supply. Depending on your electrical skills you can also make the cable.    

I have now done the test with a simple cable as suggested in John Swenson's original post. It is difficult to say whether there is an improvements or not. Perhaps a little bit more clarity and separation in certain complicated string quartet passages, but it could be just my imagination. I'll leave the grounding for a while and then try to revert. Assuming the grounding does yield slight improvements: which conclusions shall I draw from the test? Does the result imply that it would be worth upgrading to a JS-2, SR4, DC3, etc.? Does it imply the opposite? Thanks, nbpf 

[nbpf]

19 minutes ago, LTG2010 said:

I used to have an ifi supply powering a microrendu, it was good but not a big step up from the wallwart supply despite the very good specification and measurements quoted (after all its just a filltered wallwart) it does not have the ability to delivery current at speed like a good toroid, R core or Ultracap supply. Moving up to an LPS1 made a big impact for the better, more detail, dynamics, seperation.

All the supplies you mention plus the LPS1.2 will make a significant impact to your system.

They do not 'sound' the same and that's difficult to measure, the LPS1.2 is brighter and leaner than the JS2 which has a warmer sound with bigger bass, the DC3 and SR4 somewhere in between. The DC3 is best with the mundorf caps option that really elevates the sound.

I'll have then to get one of those expensive beasts, I'm afraid! I have not mentioned the LPS1.2 because it appears to be limited to 1.1A. That should not be enough for a Raspberry Pi 3B+ with DigiOne and  HDD. Thanks for sharing your findings! 

[nbpf]

4 minutes ago, barrows said:

I would not recommend using a single power supply for multiple components if your goal is best performance, as this just shares the noise from one component to the next.  SBooster linear supplies are good performers at less cost.  "Best" power supplies are going to cost some $$ though, no way around that: still do not spend a bunch of money on an expensive supply and then share it amongst multiple components, as that just defeats the purpose.

I would not change the topology, just the power supply. It's just that the LPS1.2 does not seem to be suitable to power a Raspberry Pi + DigiOne + USB drive which is what I currently do with the ifi. I have meanwhile done some more listening and I think that the JS grounding is an improvement, thanks again for pointing the attention to this issue.