Article: The Value Proposition In Computer Audio: Nuts, Bolts, and Building Blocks - Building a Home for Your Player Software Part 2

[davide256]

Thanks! Haven't played with an RPI4 yet, did you find the USB out improved vs the RPI3b+?  Played around with a variety of these devices about 18 months

ago but could never get USB out from the RPI3b+ to be as clean as a microRendu.

[davide256]

24 minutes ago, bluesman said:

If you used the stock Pi SMPS and powered your DAC through USB with any other USB peripheral connected, you weren’t getting all the 3B+ can give.

 

On basic program material (eg 2ch DSD or lighter, little or no DSP) that doesn’t overstress the 3, I don’t hear a difference between 3B+ and either USB bus on the 4 through DACs that are getting enough of their own clean power.  But when feeding DSD files from a USB HDD without its own PS while playing them back through a USB DAC using USB power, I think the 3‘s grainy and suspect it’s from borderline low voltage plus slight data flow interruptions.
 

To Chris’s point, I’ve never owned a microRendu and have only heard them a few times in other people’s systems. From memory, I think SQ from Roon Bridge on a 4 gig Pi feeding files of any size and complexity from NAS by gigabit Ethernet into an externally powered DAC via USB3 with no other USB peripherals connected is mighty close (if not equal) to what I remember of the mR.  I don’t recall and can’t find the CPU core count, the Ethernet spec or the various internal bus and R/W speeds for a mR, any of which may have contributed partly to this. Also, many mR buyers went for seriously over-the-top PSs because it was sold without one.  
 

 

Was using the LPS 1.2 for 5V PS in my experimentation. Oddly enough the reason I stopped using a microRendu was that it didn't scale up with improved

power supply whereas a Pentium NUC did. The criticism of RPI before the RPI4 was Ethernet and USB shared the same bus, guess its high time to go back

and dabble again since the RPI4 doesn't do that. My wife has just been asking if I could setup a music source in the living room...

[davide256]

25 minutes ago, bluesman said:

I assume you compared them into the same DAC and audio system powered by the same PS, which would be the only way I know of to compare them directly.  And I assume you’re comparing USB3 from the Pi to SPDIF from the Allo.  If the DAC had its own power for both, the only variable other than the Pi’s USB is the DAC’s USB processor(s) - and the DAC side of the USB pairing is most often ignored in these optical-vs-USB comparisons.

 

If you prefer SPDIF to USB, as many do, that’s fine and what you should use.  I’m still on the fence because I haven’t heard any truly direct comparisons myself except my Emotiva Stealth and my SMSL SU-8, both of which have optical, coax (on the Stealth), and USB inputs. The Emotiva has an older style C-media USB chip that’s simply not as good as its other digital inputs, and the difference is audible.  But the SMSL (v2) has much better USB circuitry that sounds little if any different to me from optical - I doubt that I could identify one from the other blinded.

 

Stay safe and enjoy the music!

There is a trade off using the Digione vs using USB out for the RPI3b+. The Digione has a sweet sound, few digital nasties but it didn't resolve transients they way

USB out did... but the USB out had digital irritants. I even "hacked" the PS input to the Digione so that it could be independently powered but it made no difference.

It's tempting to try the Signature Digione , better clocks and circuit board.