Raspberry pi DAC : USB or I2S ?

[Heckyman]

So I think what I’m hearing is that there’s no inherent technical reason why a HAT DAC would sound better ( or I suppose worse) than a USB DAC.

it all depends upon design, implementation and the chipset used.

Yes, more or less...

Not quite your original question but since the Pi2aes was mentioned upthread, there are actually 2 broad categories of i2s interface: short distance i2s (for internal connections such as RPi to hat), and long distance i2s (for connections to external DACs).

To give an example, my (external) DAC has 4 inputs: i2s (RJ45), SPDIF (AES / BNC), USB, optical.

"all things being equal" (!) the quality according to the designer goes in the order mentioned above. However, almost no sources currently available today output that particular flavour of i2s! The Pi2aes does actually come close and could probably be made to work with some re-wiring. BUT, is a $150 streamer over i2s going to sound better than say, the dCS Network Bridge over SPDIF or a state of the art server via USB? Just because of the type of connection? No-one can say until they tried it, but I doubt it. It's not just the connection method that matters. For example, how has the interface has been done internally in the device? It may be that everything comes off the USB bus anyway before being routed to the other outputs. In such a case there would be no advantage to i2s.

 

[booja30]

Yeh cos the pi is a source of ghastly emi/rfi and pi dac hats are seriously limited by board area.

I don't think board area is too much of a limiting factor unless you're trying to really overdo it like Denafrips et. al.

As an example, neither HifiBerry's low end (DAC+ Light) or high end (DAC+ Pro) hats seem to be out of room:

 

[sq225917]

I run an iancanada dual ess9038qm dac, its a busy board and even then the 3 psu rails come from an external supply. Sure, its a tinkerer's toy, with lots of options but the real estate limitations can't be ignored.

 

[adamdea]

Yes, is there any valid reason why a £90 hat DAC is better than a £90 usb DAC or even on par with, say, a £500 usb DAC ?

The short answer is no.
And in practice most of the most common ones seem to be inferior to a half way decent usb dac. Many use a less than state of the art TI chip and in some cases the supposed advantage of I2S is wasted by having the dac as slave. Fortunately they are find of fun, though, and may well be good enough. In terms fo bang for your buck it's diffcult to beat one of the cheap chinese usb dacs such as a Topping D10S which is hardly enormous.
compare
https://www.audiosciencereview.com/...topping-d10s-usb-dac-and-bridge-review.14859/
with say https://www.audiosciencereview.com/...w-and-measurements-of-hifiberry-dac-pro.8555/
or https://www.audiosciencereview.com/forum/index.php?threads/iqaudio-pi-dac-pro-streamer-dac.10374/
[in fairness all 3 are less than £90]

 

[ClothEarsAndy]

The short answer is no.
And in practice most of the most common ones seem to be inferior to a half way decent usb dac. Many use a less than state of the art TI chip and in some cases the supposed advantage of I2S is wasted by having the dac as slave. Fortunately they are find of fun, though, and may well be good enough. In terms fo bang for your buck it's diffcult to beat one of the cheap chinese usb dacs such as a Topping D10S which is hardly enormous.
compare
https://www.audiosciencereview.com/...topping-d10s-usb-dac-and-bridge-review.14859/
with say https://www.audiosciencereview.com/...w-and-measurements-of-hifiberry-dac-pro.8555/
or https://www.audiosciencereview.com/forum/index.php?threads/iqaudio-pi-dac-pro-streamer-dac.10374/
[in fairness all 3 are less than £90]

Interesting. It seems few people on ASR have been asking the same question. I'm currently running an SMSL Sanskrit 10 mk II which is another cheap Chinese DAC that gets good reviews on ASR. I'll probably stick with it for now.

The whole things just a bit messy with three boxes (pi, DAC, hard drive) and two power supplies ( one for the pi, one for the DAC) and seemingly a dozen cables Maybe I just need to box it all up a bit neater.

 

[suzywong]

Three of my RPi streamers use IQAudio DAC Hats. They're pretty d@mn good.
One of my RPi streamers runs SPDIF (IQAudio) to a Numerik. I prefer what this combo does over the IQAudio DACs.
One of my RPi-based Streamers (Allo USBSig/DigiOneSig) runs SPDIF to a nDAC-XPS. This combo is the best of the lot.

 

[Del monaco]

Three of my RPi streamers use IQAudio DAC Hats. They're pretty d@mn good.
One of my RPi streamers runs SPDIF (IQAudio) to a Numerik. I prefer what this combo does over the IQAudio DACs.
One of my RPi-based Streamers (Allo USBSig/DigiOneSig) runs SPDIF to a nDAC-XPS. This combo is the best of the lot.

I had IQaudio but a new Hifiberry spdif into my Sabre Dac is slightly, and I mean slightly, more detailed but I think it’s the Dac rather than the hat and Pi.

 

[onlyconnect]

The short answer is no.
And in practice most of the most common ones seem to be inferior to a half way decent usb dac. Many use a less than state of the art TI chip and in some cases the supposed advantage of I2S is wasted by having the dac as slave. Fortunately they are find of fun, though, and may well be good enough. In terms fo bang for your buck it's diffcult to beat one of the cheap chinese usb dacs such as a Topping D10S which is hardly enormous.

I have a D10, it sounds fantastic played through a Gram Slee solo and HD600 headphones.

Whether I could tell the difference between this and other DACs I have not tested!

I like that it plays DSD. I use Foobar with a DSD component and it removes any anxiety about not getting the best from DSD.

Tim

 

[S-Man]

Three of my RPi streamers use IQAudio DAC Hats. They're pretty d@mn good.
One of my RPi streamers runs SPDIF (IQAudio) to a Numerik. I prefer what this combo does over the IQAudio DACs.
One of my RPi-based Streamers (Allo USBSig/DigiOneSig) runs SPDIF to a nDAC-XPS. This combo is the best of the lot.

I find the PI/IQ Audio DAC+ to be quite sensitive to power supplies.
A standard wall wart switcher gives decent results. Depending on the design and components I have found that linear regulated supplies can sound better or (surprisingly) worse than the switchers!

 

[suzywong]

Yes, i've found the same thing regarding PSUs; they do seem to have an impact, even on the "digital" streamers.
The three with HAT DACs are all powered by the "official" RPi PSU (although I do have an iFi that I must try).
The RPi/IQ Digi into the Numerik is powered by a Cuinas Supercapacitor PS.
The Allo is, of course, powered by the Shanti.

 

[trick cyclist]

Suzywong
If you were to 'level the playing field' as it were with all of your pi/dacs, what order would you put them in, in terms of sounds quality? How about usability? Favourite o/s?
I'm just starting out with a lowly pi2b and a hifiberry dac hat, great fun, but configuring picoreplayer/lms was a monumental pita, and it's still not totally right! I'm actually more interested in streaming internet radio stations and spotify, which is why I went with pcp.

 

[Brian]

^

I use Volumio and it works for internet radio and spotify, not that I use spotify much but internet radio is on daily here.

 

[dan m]

Suzywong
If you were to 'level the playing field' as it were with all of your pi/dacs, what order would you put them in, in terms of sounds quality? How about usability? Favourite o/s?
I'm just starting out with a lowly pi2b and a hifiberry dac hat, great fun, but configuring picoreplayer/lms was a monumental pita, and it's still not totally right! I'm actually more interested in streaming internet radio stations and spotify, which is why I went with pcp.

Another Volumio user here. It was great for streaming BBC Radio 3 & 6 music and Spotify Connect, but having recently purchased an Auralic Altair G1 it's been moved out of my system.

 

[trick cyclist]

Big thanks Brian & Dan, I have recently been looking at Volumio, good to see it ticks these boxes, and I gather from other users that it seems to give a better sound quality than Daphile.

 

[suzywong]

Suzywong
If you were to 'level the playing field' as it were with all of your pi/dacs, what order would you put them in, in terms of sounds quality? How about usability? Favourite o/s?
I'm just starting out with a lowly pi2b and a hifiberry dac hat, great fun, but configuring picoreplayer/lms was a monumental pita, and it's still not totally right! I'm actually more interested in streaming internet radio stations and spotify, which is why I went with pcp.

OK all my systems run Moode Audio pulling flacs from my Synology NAS, using MoOde's web browser interface on PC & iPad; so they're all the same functionality/usability. They do the job...for me!

Most of the RPis are wired Ethernet, but a couple are wireless - I would always prefer copper over free space....and indeed the original wireless RPiZeroW in the kitchen suffered from dropouts and lost connections, and eventually was replaced by an Rpi3B.

It is difficult to make SQ comparisons, because they all run into different systems......which strangely do not all sound the same....

System 1 is a full-fat Naim active system into SBLs. In that context there is no doubt that the Allo USBridgeSig/DigiOneSig/Shanti via Naim DC1 to nDAC/XPS(olive) is the best sounding of my "streaming solutions".

System 2 is an Aktiv Isobarik system, with a different presentation to the Naim. All I can say here is that the RPi3/IQAudioDigi+/Cuinas PSU to Numerik is well up to the task, certainly the equal of the Karik-Numerik (again not surprising.....it's using the same DAC )

Then there is then an RPi3(wireless)/IQAudioDac/RPi PSU feeding a Denon mini system in the kitchen, an RPiZeroW/IQAudioDACZero/RPi PSU feeding SWMBO's Naim/Meridian/Kans system, another (wireless) Zero/IQAudioDACZero/HeadampZero just sitting around.

Conclusion: all sound pretty good....but of course this is only my view, and I can only report it as I find it.

Have I ever done "serious" comparisons? No, can't be arsed, let alone DBT......gawd, the rest of my life is already way too short!

Edit: I have compared my nDAC/XPS to my old Musical Fidelity V-DAC2/V-PSU1..........the nDAC won.

Not much help really.......................

 

[trick cyclist]

Au contraire, very helpful, thanks!

 

[adamdea]

Interesting. It seems few people on ASR have been asking the same question. I'm currently running an SMSL Sanskrit 10 mk II which is another cheap Chinese DAC that gets good reviews on ASR. I'll probably stick with it for now.

The whole things just a bit messy with three boxes (pi, DAC, hard drive) and two power supplies ( one for the pi, one for the DAC) and seemingly a dozen cables Maybe I just need to box it all up a bit neater.

One way of simplifying things visually would be to put the hard drive elsewhere- evn if its a usb drive you may beb able to plug it into the router. Also the pi can be out of sight Otherwise to get one box, I guess you could look at pne of these
https://www.audiophonics.fr/en/netw...for-raspberry-pi-4-dac-es9038q2m-p-14577.html
Personally I quite like the Pompidou-centre aesthetic of an uncased pi.