Allo Digione on a Raspberry Pi 4

Audio Gear Talk Raspberry Pi
1

I currently use a RP4 with Ropieee XL as a Roon endpoint feeding a Gustard DAC vis USB.

I just bought the Allo DigiOne for my Raspberry Pi and was told by a professed audiophile that with the improved USB port in the RP4, the Allo is not needed anymore as the USB is just as good or better (which was not the case with the RP3).

Is this true?

I really don’t need the Allo anymore, my reason was I wanted to have the ability to feed digital sources other than Roon (eg Sirius XM) to my DAC through the USB input and I thought the DigiOne was an elegant solution – I could route a USB to the DAC as well as a BNC from Roon.

Then it dawned on me that with RopieeXL, I can set up the RP4 as an Airplay receiver and use it for my other sources - and still use the USB port for all. At least I hope so. I have been doing this for a couple of days and it seems OK.

So I think I’ll use the Allo since it is bought and paid for, but I’m curious if I’m on the wrong track?

2

I used the Digione because my DAC only did 96/24 on USB, i later found that it had also an issue on USB. So i ran Coax from the Digione at 192/24 on both a pi3 and a pi4. Audiolab M DAC

USB on the Pi3 shared power with the Ethernet and was a bit iffy.

I am reliably informed that the pi will support USB and the Digione coax output . Maybe @spockfish can comment he is the whiz kid :thinking:

I ran the Digione on Ropieee and XL for 5 years before splurging on a Naim Unity Atom HE

To me a good buy good value

3

It depends on the DAC used, imho. Some DACs are better on SPDIF than USB. But, I use it on a Pi3 which was not a good USB implementation.

1 Like
4

If there is one rule of the audiophile is that you should never listen to an audiophile.

USB vs. Coax is completely dependent on your DAC. Some DACs have terrible USB implementations which make just about any USB source sound terrible. In that case then, yes, a Pi 3 will sound worse than a Pi 4 because of the way the bus (data and power) is run differently on those two boards. However, an outstanding USB input at the DAC can make both sound great. But a poor USB input on the DAC will still make a Pi 4 sound worse than the SPDIF inputs.

For that reason… Load XL and test both inputs at the DAC and leave the one you like. If that happens to be the USB then you have a DigiOne board you can reuse or sell or whatever. If you prefer the coax then money well spent and happy listening.

Sincerely,
ipeverywhere (audiophile for many years, decades even, and my well formed and articulate opinions are backed-up by The Internet so you can trust them)

5

I was honestly surprised by the response of the USB quality on the DAC and not on the Raspi. I’m pretty sure my pricey DAC is OK in that department.

6

A SPDIF receiver is a fairly straightforward thing as it slaves off the source. This is why “CD transports” were so coveted for their “low jitter” and other characteristics.

USB Audio is far more complicated. A perfect USB implementation needs no more than enough bits not to run the buffer to 0 from the sender. A number of XMOS chips are already gravinically isolated and some implementations go so far as not connecting the power pins to the DAC at all. Additionally, asynchronous USB modes let the DAC clock the streamer which allows for the DAC to implement whatever low jitter it wants without regard for any fancy stuff at the streamer. However, not every DAC does this or does it well. Which is why listening is your only true source of truth.

As you said, you’re “pretty sure” your “pricey DAC” is “OK” so the version of Rasp Pi you use shouldn’t make a difference… except under specific conditions where the Pi 3 can create underruns because of its design. But, if you don’t hear dropouts, it should be as good as your DAC. If you hear a difference or hear a difference between USB and SPDIF then I, generally, blame the USB implementation at the DAC and then opt for the SPDIF.

7

Try both. What do you like the sound of?

I use a RPi with RoPieee via USB and my little head-fi setup sounds great.

8

Well, I did just that. I tried both. Initially, I thought there would be no difference, but the DigiOne has a definite presence with the highs. I listened to David Elias DSD Sessions and the accompanying guitar is less distinct with USB and nicely individualized with DigiOne. Also, the DigiOne highs sounded pretty harsh on something like Hillary Hahn / Tchaikovsky’s Violin Concerto, whereas USB didn’t. It seemed the DigiOne was much better with a volume reduction with classical .

I have Roon set up so I can pick either one quickly and I’m going to do more A-B experimenting. So far there are no USB choices which causes me to winch. But there are many DigiOnes which sound much better (and visa versa)…Now it’s bugging me why I have these differences. Maybe I’m doing something wrong.