Chord Mojo(1) DAC-amp ☆★►FAQ in 3rd post!◄★☆
Oct 14, 2019 at 5:51 AM Post #39,361 of 42,765
This post is indicative of a fair amount of mis-information about the raspberry pi or any other computer for that matter as it relates to computer based audio reproduction.

I think you're either unfamiliar with the available HATs for the Pi and what they do, or you just misread his post since he didn't say anything about using the Pi itself, for which your criticisms would have been valid.

Lifting the signal generation out of the Pi and onto a power filtered clean board isn't something an optimised PC/Mac system has any chance of competing with, the hardware handicap is just too great once you add something like a DigiOne to the Pi. Every time your PC/Mac draws power its noisy power. The DigiOne works downstream of a long series of power filters and enjoys galvanic isolation, and thus gets to work comparatively interference free, as shown in its near reference measurements that are outside of the PC/Mac realm of possibility.

(I know dgozalie didn't have a DigiOne since he has optical out, I'm just using it as an example due to knowing how its set up hardware wise)
 
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Oct 14, 2019 at 5:55 AM Post #39,362 of 42,765
I think you're either unfamiliar with the available HATs for the Pi and what they do, or you just misread his post since he didn't say anything about using the Pi itself, for which your criticisms would have been valid.

Lifting the signal generation out of the Pi and onto a power filtered clean board isn't something an optimised PC/Mac system has any chance of competing with, the hardware handicap is just too great once you add something like a DigiOne to the Pi.
Handicapped which way? Pc can’t compete with hat board like digi one?
 
Oct 14, 2019 at 6:00 AM Post #39,363 of 42,765
I think you're either unfamiliar with the available HATs for the Pi and what they do, or you just misread his post since he didn't say anything about using the Pi itself, for which your criticisms would have been valid.

Lifting the signal generation out of the Pi and onto a power filtered clean board isn't something an optimised PC/Mac system has any chance of competing with, the hardware handicap is just too great once you add something like a DigiOne to the Pi. Every time your PC/Mac draws power its noisy power, the DigiOne works downstream of a long series of power filters and gets to work comparatively interference free, as shown in its near reference measurements.

I actually just placed an order for a DigiOne Signature and plan on running Volumio.

I'm excited to compare it to my current headless PC/Schiit Eitr combo I use as a source.
 
Oct 14, 2019 at 7:14 AM Post #39,364 of 42,765
Handicapped which way? Pc can’t compete with hat board like digi one?

There is no low noise environment inside a personal computer. You can use software to make sure as little CPU power is used as possible, but the issue still remains - if your components need power they only have noisy power to utilise. You can't output audio with as low jitter and noise as you can if you have a cleanly powered and audio optimised hardware environment in which you generate the signal. The better Pi HATs are just that, a little clean separate board on which your Wolfson SPDIF chip or whatnot can work without interference and output a signal with very little noise and jitter. Hence why something like the Digione measures as well as it does.
 
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Oct 14, 2019 at 7:29 AM Post #39,365 of 42,765
There is no low noise environment inside a personal computer. You can use software to make sure as little CPU power is used as possible, but the issue still remains - if your components need power they only have noisy power to utilise. You can't output audio with as low jitter and noise as you can if you have a cleanly powered and audio optimised hardware environment in which you generate the signal. The better Pi HATs are just that, a little clean separate board on which your Wolfson SPDIF chip or whatnot can work without interference and output a signal with very little noise and jitter. Hence why something like the Digione measures as well as it does.
And who is doing the measuring ? And what are they measuring against ?
 
Oct 14, 2019 at 8:30 AM Post #39,367 of 42,765
And who is doing the measuring ? And what are they measuring against ?

The figures and report sheets on their website are from independent testing - https://www.allo.com/sparky/digione.html.

And you have the ASR review confirming it to pretty much match the $20k AP audio analyzer used for measuring - https://www.audiosciencereview.com/...measurements-of-allo-digione-rpi-s-pdif.5418/

It's only possible due to the galvanic isolation from the Pi and due to it being designed competently with audio specific design objectives. The PC/Mac playback solution has major upsides for many people in terms of user experience, software choice etc, but there is a benefit to the Pi + HAT route too, mainly that it's a very cost efficient way to use high quality purpose built hardware.
 
Oct 14, 2019 at 11:20 AM Post #39,368 of 42,765
My main concern is this quote which is not qualified "all computer whatever it is windows or mac always have more interference cause they are general purpose computer, not specific computer for specific job... that explain the superiority of rasp pi for audio output."

As I stated, you CAN make a Pi into a very good playback platform with a fair amount of work. It works especially well when headless, with no attached storage and with specific hats and fancy power supplies to address its crappy busses and power contamination. Using a PC or Mac as a core with Roon and a Pi based bridge endpoint for example can sound great.

I do still disagree, that by itself and more importantly as a single box solution, the Pi is an inherently better platform, it is not.

As for Toslink, I have never experienced great sound from Toslink, probably due to it's higher inherent jitter.
 
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Oct 15, 2019 at 10:48 AM Post #39,372 of 42,765
You will gain galvanic isolation, but at the risk of increased jitter (potentially).


In more general terms:
I would have thought 75 Ohm coax via a transformer might be the optimal solution (where an electrical SPDIF output is available). Would this work?
 

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