[JN] EXTERNAL: Re: DACs for RPi zero W

Danielak, Robert M robert.m.danielak at lmco.com
Mon Apr 8 10:19:14 CDT 2019


hi gang,
yes it was me that originally asked for recommendations.
I ultimately decided on the allo mini boss.

ironically, I think the allo mini boss on RPi zero W sounds same or even better
than its big brother allo boss on RPi 3B+.

I have not tried any of larry's power supply recommendations on the boss/3B+
so maybe that will eventually give the boss/3B+ the edge.
but I'm pretty satisfied with the stock set-ups.

I'm running the latest version of moode audio on both units.
the mini is destined to go in my truck
but I've been distracted from the project for a while...

I've never believed in "good things aren't cheap and cheap things aren't good".
this is more evidence for me.

or maybe my standards are just low ;)

have fun!
bob.d.



-----Original Message-----
From: Larry Moore <larrymooreattorney at gmail.com> 
Sent: Monday, April 08, 2019 7:55 AM
To: Gable Barber <gablebarber at gmail.com>
Cc: Danielak, Robert M (US) <robert.m.danielak at lmco.com>; sound at soundlist.org
Subject: EXTERNAL: Re: [JN] DACs for RPi zero W

A really nice offer -

I know I’ve stated this here before, but it bears repeating, the Raspberry Pi has a clock that is not an integer multiple of either 44.1 or 48 kHz.  This means that it switches back and forth between two frequencies, on either side of a “center” desired frequency, in clocking data.  The result is fair amount of jitter.  You can look at DimDim’s website for the detailing of this:

http://www.dimdim.gr/2014/12/the-rasberry-pi-audio-out-through-i2s/

However, there’s a couple ways around this.  One is to reclock.  Another, and better still, is to run the DAC chip off a separate oscillator proximate the chip itself.  This takes some knows how (software programming).  In one such approach, a selection must be made between oscillators depending on whether the signal is 44.1 or 48kHz based.  In another, the DAC has some “intelligence” or programing, and this form of operation is referred to as “master mode.”

So, the DAC you offer uses none of these approaches.  It’s from what I'd call the 1st wave of DAC HATs.  It simply runs off of the “high” jitter clock provided by Pi.  It uses a PCM5102 DAC chip from TI/BB.  There are many examples of DAC HATs (hardware on top) that use the PCM5102.  It’s easy, and there’s not a lot for a designer/builder to screw up - the DAC chip includes an on-board I/V conversion, and is thusly, voltage out.  And, it also contains a charge pump, so it will run off a single +5 volt supply.  The layout and, in particular, the charge pump capacitors are important to the sound.  But, again, there’s not a lot to get wrong…. Frankly, many of these are better than the vast majority of CD players.

First in the next or 2nd wave of DAC Hats, was the HiFi Berry DAC + Pro.  This uses the PCM5122 - a programable version of the PCM5102, and has the benefit of running off of one of two oscillators, as I mentioned above.  It sounds much better as a result.

There’s also some ESS9023 DAC based DAC HATs, but personally, I always hear the on-board reclocker - not for me.  Sounds like the early ESS DAC implementations you typically hear - lots of detail, but tiring, and ultimately, unnatural.

Allo, then came out with the Boss DAC.  I was a beta tester.  You want a version 1.2 as there were major power supply changes between the 1.0-1.1 and the 1.2, the 1.2 being a good bit better.  In my, and many others whom ears I trust, the Allo Boss ver. 1.2 is the best sounding PCM5122 DAC HAT.

It takes major - ask me how I know - modification to a HiFi Berry DAC + Pro to get one to sound as good as Allo Boss DAC ver. 1.2.  Further, you must be pretty good with surface mount soldering and be ready to throw multiple different, highly selected power supplies at the problem…. In comparison, the Allo Boss DAC ver. 1.2 is pretty much turnkey, though it too benefits from better and select power supplies.  There’s an isolator board available too.

Allo now offers a miniBoss for the PI Zero, but I haven’t heard it.  I believe that’s what  Bob D. Pointed to.  There’s some pros and cons to the Pi Zero though, and for the difference in money, I’m not sure I’d bother.  Depends on what you’re trying to accomplish…but, this can be stupid good for the money.  Very, very few vintage CD players and/or transports and DACs are at this level if the Pi/Boss are set up correctly with appropriate software.

The next major step forward in DAC HATs, and perhaps, a 3rd wave is the Allo Katana.  This uses the latest generation ESS DAC chip, the ESS9038Q2M.  It 2-channel DAC chip from the “mobile” electronics line.  The hone or Pro chips have multiple DACs inside.  I think I have a Katana completely optimized using some pretty select reasonable mods and several select power supplies - I can go into detail, if there’s interest.

I recommend MoOde Audio.  It will allow you to stream radio stations, and has the ability to be used with Tidal too.  NAS or local HDDs for the rest of your files.  It make you never want a tuner or CD player or transport and DAC or computer and DAC ever again, all the while allowing you to explore new music…

Pretty close, if not, SOTA for again, stupidly low money outlay.

Gotta run, HTH
 

> On Apr 7, 2019, at 11:43 PM, Gable Barber via Sound <sound at soundlist.org> wrote:
> 
> HifiBerry makes one:
> 
> https://www.hifiberry.com/shop/boards/hifiberry-dac-zero/
> 
> I've got a spare one, if you want to try one, drop me a line and I'll 
> mail it to you.
> 
> Cheers~
> 
> On Wed, Jan 23, 2019 at 11:16 AM Danielak, Robert M via Sound 
> <sound at soundlist.org> wrote:
>> 
>> Any suggestions for DAC hat for RPi zero W?
>> I’m happy with the Allo boss on RPi 3b+.
>> Any tips would be appreciated
>> Thanks
>> Bob.d.
>> 
>> Sent from my iPhone
>> 
>> _______________________________________________
>> Sound mailing list
>> Sound at soundlist.org
>> http://mailman.soundlist.org/mailman/listinfo/sound
> 
> 
> 
> --
> Regards,
> Gable Barber-Smith
> 
> _______________________________________________
> Sound mailing list
> Sound at soundlist.org
> http://mailman.soundlist.org/mailman/listinfo/sound




More information about the Sound mailing list