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Review and Measurements of Allo Katana and ApplePi Raspberry Pi DACs

March Audio

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#41
But none of these things are objective, why should they even be discussed. The Alio is better, end of discussion?
From my POV I wouldn't hesitate to use the Allo, but I'm not an audiophile ;)
 

helloworld

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#42
Hello everyone

first a big thx to Amir . I am a fan since he tested the uRendu and seen the extent that some manufacturers go to shade clear test results.

We decided to be diffrent , instead of hiding and arguing , we want the test to speak for themselves. We want to embrace the comunity and be open.

This is our Katana. Above are Amir test results (and we have the same readings)

Now some of you ask about our changes to Katana (Katana 1.2). Look at the above results , roll off is a bit higher than normal and the 88Khz noise...it was audible in one of our test setup.So we changed the filtering...and now roll off is much deeper and the 88Khz is gone. (we removed the R in front of the RC low pass filter)

Please note that jitter (for us) is one of the most important qualities in a DAC

Since we had some time in our hands we also looked at power rails and we decreased the noise on the dual rails feeding the opamp (from 2.7mV to 900uV). One thing we are observing is that THD+N decreased further (Katana 1.2) to (unweighted) from -111 varying to -112.2 (still more testing is required before we make this claim)

So please be patient but we think that our DAC can compete with the best of the best.
hi, thank you for your great product, it looks really amazing. I only have two questions, 1, is there any reason why the dynamic range from this test is a little bit lower? 2,why not directly adding the xlr output? It would probably only add 5 bucks while we do not need to solder by ourselves.
 

Olli

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#43
Amir, but if you choose Roon Bridge as the player - why do you still need to use airplay and volumio?

Oh I can. It is just that airplay in volumio can't handle 24 bit content which messes up the measurements.
 

amirm

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#46
And how exactly is airplay related to your measurements?
Airplay has a limit of 16 bits and 44.1/48 kHz sampling. The latter is not an issue but the former is, when you try to measure SINAD and jitter components beyond 16 bits. Using Airplay and Roon, I could only get a sinad of about 94 dB because of that limit. And FFT spectrum showed lots of noise components indicating truncation. Here is that dashboard view (through Roon and airplay on Volumio):

airplay dashboard.png


ALL my normal testing is with 24-bit source so having it truncated to 16 bit by airplay is not proper.
 

amirm

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#47
Sorry I was typing on the phone so too brief. :)

Roon can access networked DACs using either Apple Airplay or Roon's own protocol called RAAT. Volumio which came pre-installed on the Pi that was included on Katana only supports Airplay. Using that, I had no problem playing music using Roon to Volumio and Katana. The issue here was that for measurement purposes I need to have a bit-perfect, 24-bit audio pipeline which airplay does NOT support.

Other Pi OS packages do support RAAT. I just have not had good luck installing them and getting them to work.
 

Krunok

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#48
Amir, but if you choose Roon Bridge as the player - why do you still need to use airplay and volumio?

Airplay has a limit of 16 bits and 44.1/48 kHz sampling. The latter is not an issue but the former is, when you try to measure SINAD and jitter components beyond 16 bits. Using Airplay and Roon, I could only get a sinad of about 94 dB because of that limit. And FFT spectrum showed lots of noise components indicating truncation. Here is that dashboard view (through Roon and airplay on Volumio):

View attachment 14943

ALL my normal testing is with 24-bit source so having it truncated to 16 bit by airplay is not proper.
Ok, but why are you using the airplay in the first place?
 

Krunok

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#50
Sorry I was typing on the phone so too brief. :)

Roon can access networked DACs using either Apple Airplay or Roon's own protocol called RAAT. Volumio which came pre-installed on the Pi that was included on Katana only supports Airplay. Using that, I had no problem playing music using Roon to Volumio and Katana. The issue here was that for measurement purposes I need to have a bit-perfect, 24-bit audio pipeline which airplay does NOT support.

Other Pi OS packages do support RAAT. I just have not had good luck installing them and getting them to work.
Ok, now it's all clear. :)
 

Krunok

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#51
Sorry I was typing on the phone so too brief. :)

Roon can access networked DACs using either Apple Airplay or Roon's own protocol called RAAT. Volumio which came pre-installed on the Pi that was included on Katana only supports Airplay. Using that, I had no problem playing music using Roon to Volumio and Katana. The issue here was that for measurement purposes I need to have a bit-perfect, 24-bit audio pipeline which airplay does NOT support.

Other Pi OS packages do support RAAT. I just have not had good luck installing them and getting them to work.
Maybe this can help using Roon with Volumio directly (read post #3 by user wizardofoz): https://volumio.org/forum/roon-labs-t3311.html

And this: https://community.roonlabs.com/t/roonbridge-on-volumio-raspberry-pi-image/10170/9
 

DonH56

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#52
Some jitter background in these two threads (but I make no attempt to define what you think will be audible):
https://www.audiosciencereview.com/forum/index.php?threads/digital-audio-jitter-fundamentals.1922/
https://www.audiosciencereview.com/...igital-audio-jitter-fundamentals-part-2.1926/

Note SNR loss due to jitter depends upon the bit depth (resolution) and signal frequency -- no (direct) dependence upon sample rate.

Jitter, at least some form of it, can be derived from a phase noise plot and thus phase noise and jitter are related. Integrate phase noise over frequency and (with a little math) you get rms jitter.
 

amirm

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#53
I am VERY surprised that the spectrum is very similar to yours. While it looks like my X-Fi has less spreading, but due to the limitation of ADC (which also adds noise) and different windowing/averaging parameters, I am not so sure if it is an illusion or not. Notice the pattern at around 18kHz...
There is definitely some similarities. I have seen that 18 kHz pattern in other DACs too.
 

Soniclife

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#54
Other Pi OS packages do support RAAT. I just have not had good luck installing them and getting them to work.
Can someone in the USA send Amir a memory card with one of these pre installed on it, it seems his PC must have some special Bill Gates Linux patch on it ;).
 

amirm

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#55
Here are the IMD test results at 6 pints from -50 dBFS to 0 dBFS in 10 dB increments. The dashed line is the much higher resolution output of Topping DX7s created over USB from my computer. The red is also Topping but now driven by those few steps using Volumio. It kind of, sort of shows the "hump."

Katana and ApplePi show better results across the board and without that hump.

1534977747947.png


The data is pretty coarse though. I would need to add more steps to be definitive.

As it is, it points to something specific to ESS DAC and how Topping buffers its output.

Boy, manual testing is so time consuming!
 
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#57
What do you think about this compared to Topping D50? Both are about the same in price.

This is a bit more work vs Topping but can be easily upgraded in the future with different boards/DAC chips.

I am just asking in terms of performance/measurements. Amir did not directly compare this to top performing units from this site, but any comments on which you think performs better based on his testing of both units?

Thanks
 

helloworld

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#58
What do you think about this compared to Topping D50? Both are about the same in price.

This is a bit more work vs Topping but can be easily upgraded in the future with different boards/DAC chips.

I am just asking in terms of performance/measurements. Amir did not directly compare this to top performing units from this site, but any comments on which you think performs better based on his testing of both units?

Thanks
If you can get a Topping D50 from China(ask a Chinese friend to buy from taobao.com), it's about $190, then use the EMS to ship to US, the shiping expense is about $10-20. So total cost is $200-210. which is less than $249.00(actually if you consider buying the case and 2 5V3A psus and the DC to Type-C USB Adapter Cable, it may cost more).
 
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#59
Thanks. I was actually thinking of buying this with RPi and case/cables, which is more like $350 altogether (Allo cells the package or I can buy separately). I am willing to spend a bit more to have an option of easily upgrading to a different DAC board later on. But was trying to find out how the measurements of the units would stack against each other. Does one perform significantly better than the other?

Also, saw D50 on ebay for $219 with free shipping (still there I believe).
 
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