Hi!
I´m new to Volumio and am evaluating if it’s for me.
Just recently installed it on an old raspberry pi 3 I had laying around. But ordered a 4 and a better case.
I have an external DAC (RME ADI-2 FS) which would be the best solution for connecting the raspberry pi 4 to the DAC, USB or spdif?
This setup is for my bedroom, listening to a pair of headphones and a small 2.1 system.
I will mostly use it for my Flac library but also for Spotify.
Thank you!
Volumio runs really well on a Raspberry pi 3A or 3B.
After a lot of trial and error I have finalised on using a digi HAT with S/PDIF into an external DAC. Another significant influence on sound quality is the power supply that you use. an iFi iPower 2 is a worthwhile investment but you need to keep in mind the power needs of a Raspberry Pi 4 which tends to be more than a Raspberry Pi 3.
Good luck
Thanx!
Considering Pi3 issues with USB I won’t use it.
Will start with USB Pi4 and maybe add HAT later.
I also had a Pi 4 for years and was very happy with it. A DigiOne hat and S/PDIF yielded further improvement, but the most noticeable difference was obtained by a good linear power supply (I bought a Tomastik). A few months ago I bought a Rivo and that added an edge yet. I use it mostly with the S/PDIF coax out, which I like slightly better than the USB. But the differences are tiny and it certainly depends on your DAC.
RPI4 has no issues with USB DACs. The problem with the RPI3 and some S/W is that there can be pops and break up of the sound. Very obvious, not subtle! The RPI3 problem is documented on GitHub and as you know the problem can be eliminated with a HAT but that costs money and you need a large RPI case etc.
Most emphatically if you are using a DAC of the quality of the RME it will have good immunity from RF noise and packet noise from the USB port (possible exception if you are wiring to a very old noisy gaming PC wit a LOT OF POWER SUPPLY NOISE). Read Archimago or Audio Science Review if you want confirmation on this - they have done detailed and measurements and blind audio test…
The RPI4 needs an RPI4 power brick or equivalent - not an expensive linear power supply which is a waste of money - the RME will handle any very slight noise and its audio output will be perfectly clean even when driving absolute top notch amplifiers and speakers (say >$10K)
A compact heatsink case like those supplied by FLIRC will keep the RPI4 cool and also protect the RPI4 board
EDIT: I imagine that the RME DAC came with a standard USB cable. This is ideal. An expensive ‘audio’ USB cable will not improve the sound.
Many thanks for the input!
Yes, I suspect RME is very good in this regard, maybe even great depending on to what one compares it to.
I’ve purchased the official RPi4 PSU, which I assume will be enough, especially since I do not plan to add a HAT for now.
Regarding the USB cable, I do use a 3rd party one, simply because I like the look and feel of it. But i know RME has debunked the myth of fancy USB cables being a factor. 
Really looking forward to getting this set up!
RME is a very professional company and they understand what their customers need. Some of the best DACs and well engineered.
I’m sure your new setup will be great!
Hi, apologies if a bit late but just thought I would add my experience as a relatively new user. I have a Pi4 with ifi power supply into a Cambridge Audio DAC via USB and the Pi is hardwired into the router via a good quality network cable (not wireless). The DAC is external into a high end hifi system. I use Tidal for streaming via Tidal connect (which works flawlessly by the way) but most of my music is ripped from CD to a 1TB ssd plugged into the Pi, which also works flawlessly. USB is the way to go in my opinion, especially if you’ve a good DAC - it also handles up to 192k without issue - not sure SPDIF can do this(?). Ignore what people say about digital interconnects (especially amir at audio review science) - they DO make a difference sonically. But there’s no point spending alot of money - £30 or so is enough, an Audioquest or similar as its only a Pi at the end of the day. I also use a Jitterbug which seems to help with timing. Addition of the ifi power supply hasn’t made a notable difference in terms of sound quality (that’s because a Pi4 is alot better than a Pi3) but it has made the power supply very stable and I rarely get any issues with needing to reboot. At the end of the day, I am still gobsmacked at how good this inexpensive piece of kit can sound with care on the connections and set up. It holds its own against dedicated audiophile streamers costing considerably more. Hope you enjoy yours.
I have a RPi 4 and is using USB to a dac. Works great. Don’t see any need to get a hat unless you buy a very good dac and want to compare usb to spdif.
I used to have a RPi 3B with a hat but that model did not have a good usb out.
That is a very nice DAC.
The SPDIF protocol was designed for digital audio transmission. SPDIF is a very old protocol released at a time when memory buffers were expensive and CPU bandwidth was measured in MHz. SPDIF facilitates jitter suppression by embedding the source ‘word clock’ within the digital stream. A poorly designed DAC may still suffer from excessive jitter however.
Your RME DAC is a well designed and modern device. To suppress jitter the RME buffers the incoming digital stream and re-clocks the stream internally, defeating any need to extract the word clock from the source stream. I would say your answer is USB.
If you had a cheap, poorly designed or old DAC that lacked adequate buffers and an internal clock SPDIF might improve it. However a better answer would be to buy a better DAC.
Early in my career I worked in computer/digital telephony transmission; recording, encoding and squirting PCM over Ethernet before anyone said VOIP. I’m more production, test and operations than design but like to think I have a better than average grasp of the theory and physical implementations.
I would really like to hear ‘how’ you believe Amir has got it wrong? I just read the thread I think you are referring to and the results produced align with my understanding and experience. It appears to me that Amir is more knowledgable on the specifics than I am.
I am open minded to the idea there is something I am missing and I am aware the internet is populated by a few charlatans. But please. If you are going to contradict the common understanding in the field and tell me not to believe someone who appears to have expertise, I need more than your word. I need reasons. Why should I believe you and not Amir.
Hi there. Where to start. The rabbit hole of cables and whether they do or don’t make a difference. There are often strong opinions on both sides of the debate and as you say there are charlatans and snake oil salesman abound. Typically, people of the view that cables don’t make a difference are often involved in the computer industry and, paraphrasing, say its all bits, numbers and binary. It makes no difference - a zero is a zero and a one is a one. And Amir for example says, again paraphrasing, I’ll test this scientifically and prove its the case. And he also tests pieces of hifi equipment and if they dont measure well technically, especially if theyre expensive, concludes its snake oil. And to be fair sometimes it is. But, music is an emotional experience that requires us to listen. Swapping out cables can create an audiable difference regardless of the fact that technically speaking they shouldnt. Try it. I’ve carried this exercise out with many people many times over the years and with very few exceptions, almost everyone hears a difference. I’m not saying it’s necessarily better, I’m saying different. Its up to the listener to decide what they prefer or even if any difference is worth spending money on. Our ears (or rather our brain) can fool us of course and that’s why blind listening is I believe the best solution. That takes away the element of cost or value influencing the decision. And this is something I believe I’m right in saying with regard to Amir, that there’s no listening of what he tests takes place because he believes it’s all subjective. Well yes, it is subjective - that’s the point. Measurements tells you so much. Listening tells you as well. My original post was intended to be helpful but I realise Ive made the fatal mistake of including a reference to cables! Anyway, try it for yourself if you can and make your own decision.
Thanks for taking the time to provide your rationale.
Are you claiming learning how computers work affects one’s ears. Or possibly those with a natural aptitude are born with strange ears. 
I guess not.
What I see as the big red flashing flaw in your rationale is the conflating of the analogue and digital domains.
You can be as subjective as you like in the analogue domain. Analogue is unpredictable and unrepeatable. There are an infinite number of voltages between any two measurements. Placing a current on a wire will change it. So on and so forth. There is a lot of scope for vague and subjective difference.
The digital domain is artificially constructed from discrete values and protocols. The space to be vague or different is deliberately engineered away. There is exactly one unpredictable value in the digital domain, which is time - When exactly does a digital 1 occur. We can predict the 1 occurs at the near end some time before it occurs at the far end. That difference is (in simple terms) jitter.
As Amir showed with his carefully selected worse case the properties of a cable can influence jitter; because the cable is analogue and transmission occurs in the analogue domain. I am willing to believe some people are sensitive to jitter. It is digital noise after all, unnatural and perceived very differently to analogue distortion. I do not believe in super-humans however. I would say no one needs a special cable for digital transmission, simply one that meets specification and is not marginal or faulty.
You may believe you can hear a subjective difference between a $10 USB cable and a $300 USB cable but it’s similar to believing in a flat Earth. There is no physical or scientific evidence to support the belief and a lot of accepted facts that debunk it. I certainly have never noticed a difference in the dozens of cables I have tried with dozens of digital audio devices. (Ahh but I’m lacking the secret knowledge of that one special cable I would hear - Oh dear.)
I defer to the advice I gave earlier. If you think you can hear a difference between digital cables that are not faulty, I think you need a better DAC.
here is an interesting read on this matter:
https://www.thewelltemperedcomputer.com/KB/USB.html
Agree with most of the above comments…
I’ve got a RPi4 > USB > RME Adi2 FS and it’s a brilliant setup. There are no need for hats these days, they are fiddly and pretty expensive (at least delivered to AUS), the sound from USB isn’t an issue like the older RPi’s, and is totally fine. Optical and Coax are the only option with some equipment but these days I feel USB is better (plus you don’t get conned into buying overly expensive interconnects.
Any normal cat cable is fine (i’m using a cat 6 slim). I’m sure wifi would be fine too but my router is conveniently nearby.
Hat’s make it hard to use the offical RPi touchscreen too (which I added later).
Cheers
I also have a RPI4 (with FLIRC case and standard power brick) feeding into an RME AFI-2 DAC with a basic USB cable. It sounds great through my Genelec desktop speakers. The RME DAC has a bit test feature which confirms the accuracy of data transmission from my NAS drive through the RPI4/Volumio onto the RME and this passes for all the sample rate and bit resolution test files.
