USB or I2S DAC?

Hi everyone,

what kind of DAC would you recommend, one connected via USB or I2S to the RPi?

Today I had the chance to test a Meridian Explorer on my RPi (from my father-in-law). I had no issues, just connecting, booting the RPi and playing music via AirtPlay without any issues.

I don´t know where but I remember that I have read that the USB port from the RPi is some like problematic, so some people prefer the I2S port.

What do you prefer … a USB or I2S DAC?

i’ve used a es9023 in sync mode trough a WaveIO USB->I2s (xmos based) and the es9023 in async durectly to the i2s line.
i prefer a lot the latter, much more stable setup and less noise-click-pop issues (especially at high sampling rate/bit depth).

keep in mind that in your “USB” dac, internally, there is a usb->i2s converter anyway so, why you prefer to add another element on the chain when you simply skip extra steps ?
sometimes less sound much more better than a more pricey and complex setups. give it a try.

Hi, thank you for your reply.

I’ am not very familiar with all the technical background of the matter. Please could you explain your setup a bit more? (Is it like this? - raspyfi.com/building-my-reference-dac/)

I understand and know that not always the price makes the quality. The Meriadian Explorer is not my goal at the end. I’ am looking for smart solution with the best relation in price and sound quality.

I prefer a USB DAC that outputs analog directly. … something like http://www.logicform.net/. Simple usb in (powered by the bus too) and clean analog out to the amp.

much more like that : diyinhk-es9023-dac-t713.html

i2s is also (usally) much more cheaper… so if you wanna go on budget, use i2s directly.

Hello
Please take an I2S Dac! e.g. HifiBerry-Dac.
I have made the experience that the HifiBerry-Dac clearly sounds better than my Musical Fidelity V90-Dac.
Even over Coaxial sounds of the V90-Dac much better than USB. USB is useless in my opinion!
I had the RPi connected by a M2Tech HiFace Two (USB-S/PDIF).
Where the USB problem as also existed.
(The heights are identical, but the bass better - more accurate)

Still a bit better than the V90-Dac (Coax) sounds the HifiBerry-Dac!

My recommendation - HifiBerry-Dac!

Have fun!

rost21A

Hi rost21A,

I read very often from the HifiBerry.

What I miss is a comparison against a Texas Instruments PCM1794A or ESS Sabre 9023 DAC.

Can anybody say something to the three opponents?

Has no one experiences with the HifiBerry and a ESS Sabre or similar?

Hello
I’m not a super expert, but BurrBrown are known for very good converter chips.

regards
rost21A

I have two Raspi’s running Volumio. One uses the DIYINHK Burr-Brown PCM5102A i2s board and the other uses an ESS Sabre 9023 i2s board. I believe its difficult to pronounce a ‘winner’ between the BB chip and the ESS chip - it depends on the implementation of the particular chip (choice of components, power supply components etc) and, perhaps most importantly, the quality of the power supply you use.

Bottom line, if using a cheap power supply and powering the DAC from the Pi’s onboard power pins then there’s no huge difference - you can go with either.

If you use a good quality linear power supply (I power the Pi with one supply and power the DAC with a second linear PS) then there is a small difference between the two but, again, it’s not a ‘one is better than the other’ kind of difference. The ESS is slightly warmer and the TI chip (Texas Instruments owns Burr-Brown) a little leaner. All comes down to your personal taste. I could live happily with either. The power supply is a big improvement - definitely moves the sound up several notches. All this is my own 2-cents of course…

Hello,

I’ve started my Volumio solution with this one :

http://www.audiophonics.fr/audiophonics-usabre-diy-mini-usb-dac-24bit96khz-sa9023es9023-p-8427.html

Works fine but limited to 24bit/96Khz.

for now i use the I2S to analog posted here :

http://volumio.org/forum/ess9023-with-t582.html#p3321

May I ask, what power supply do you use?

I started out with two separate home brew linear power supplies based on the lowly (but surprisingly good) 7805 regulator. I then tried a sealed lead-acid battery (commonly available from burglar alarm supply chains) and then one of the 4-rail DIYINHK power supplies. Currently I use one rail for the Pi and one rail for the DIYINHK ES9023 DAC.

As to which sounds better - if I had to choose I’d probably take the battery but the differences are very subtle and seem related to the time-of-day you compare. Late in the evening there doesn’t appear to be as much ‘noise’ on the mains and it’s hard to hear a difference between the DIYINHK or 7805-based mains-connected power supplies and the battery-based power supply. At other times of the day (mainly 8-5) I prefer the battery. May be mind-over-matter but…

@DerekR

Can you show us your setup, especially the power supply?

Sorry, Tomcek, only just saw this post. I’ll post a couple photos later.

The current incarnation uses one of the recent two-rail DIYINHK power supply boards fed by a dual-output toroidal transformer sourced from Farnell in the U.K.

One rail powers the Raspberry Pi and the other rail powers the DAC. I mounted the toroidal xfmr, power supply board and Raspberry Pi between two 6"-square pieces of 1/4" Perspex using aluminum tubing as spacers. Quite simple with hand tools. The DAC is mounted above the Pi on a standoff and connected to the P5 I2S pins of the Pi with a short harness. Because the ES9023 and PC5102A boards from DIYINHK are similar in size and placement of I2S, power and audio out connectors they can be interchanged quite easily.

The audio output of the DAC goes via 3/4" cryo treated silver Litz cables to a pair of tellurium copper RCA female jacks that have screw connectors as against solder connectors. The AC input to the toroid is via a tellurium copper IEC input. Both the RCA females and IEC input were sourced from Taiwan and are mounted on a vertical 1/4" Perspex plate on the same side of the unit as the Pi’s Ethernet/USB jacks. I also implemented birca’s IR control (instructions elsewhere on this site) using an Apple A1294 remote. Three unused speaker spikes on the bottom and it’s a surprisingly neat and, IMHO, elegant little server/DAC.

To further muddy the waters you could also try running the Pi/DAC from battery power. I used a combination of parts available from most burglar alarm supply stores to put together a battery and charger supply that could provide 12v to an ALIX board. The Pi/ DAC needs 5V so you’d need to run the battery’s output through a regulator - something like an LT3080 like Michaelangelo used on this site - and then into the Pi and DAC.

For those interested (and to save me rewriting) there’s a couple of posts on Computer Audiophile that give a how-to: computeraudiophile.com/f10-m … dex15.html have a look at posts #353 and 357.

If only michelangelo would provide an updated kernel for the wolfson pi dac (element14.com/community/comm … CC-Wolfson) :slight_smile:

Until then for me the best combination is:

Volumio kernel + O2 Objective USB DAC (headnhifi.com/dac/odac-35mm)

I think Michelangelo needs another head and a further 3 pairs of hands to keep up with all the demands being made on him!

He did say in another thread he was getting a Wolfson card (this week?), so presumably support in Volumio will follow after that.

I see there’s an interesting development for the Raspberry Pi itself, the Compute Module raspberrypi.org/raspberry-pi … w-product/

I guess that might result in multimedia products with the Pi embedded?

Yes, that new announcement is truly exciting. It should spawn a load of new, tailor-made base boards specifically for audio. I can see a ton of immediate improvements - no un-needed, non-audio-specific components, embedded DACs, properly implemented I2S traces, hey, maybe even Femto clocks on the base board!

Definitely a step along the evolutionary road for applications like Volumio which use the Raspi.