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PI2AES Digital Audio Shield for the Raspberry PI

Michael Kelly

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Aug 22, 2018
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#1
Folks,
We have just finished testing the protos of our new digital audio shield. This replaces our 502DAC for digital audio out. This unit has the following features:

Woflson WM8804 AES Transmitter with dual NDK Low Noise Clocks
SPDIF COAX via RCA
SPDIF Optical
AES Balanced via XLR
Direct Buffered I2S via Header, with I2C, 5V and VIN Power
LVDS Differential I2S via HDMI with support for Gustard or PS Audio pinout (selected at time of order)
Single 12V to 48V input, with on-board [email protected] supply
Separate Ultra low noise LDO's for WM8804 and NDK Clocks

Below is a photo of the unit.



Test results and comparisons to 502DAC. Note that the 502DAC board I have here on the bench has a broken XLR. Once I get another in hand I'll add that test. I can't even keep a unit for myself since we are always back ordered!

502DAC BNC. This is what everyone has been very happy with, yet clearly there was room for improvement.



PI2AES RCA. Noticeably better than 502DAC BNC.



502DAC OPTO Jitter. Yikes!



PI2AES OPTO Jitter. Huge improvement over 502DAC Opto, but still not as good as P2AES RCA





PI2AES XLR Jitter. Note that the results seem to be a bit worse then the PI2AES RCA. But XLR is needed for long cable runs or interfacing with pro audio equipment.


Cheers,
Michael
 

Michael Kelly

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#3
Good job, Michael! Thanks for sharing your results.
From your lips to Amir’s ears! Maybe he’ll promote me to the front page? Hint, hint.....

I’ll be linking to the data sheet and hw reference manual sometime this week.

Michael
 

headshake

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Apr 20, 2019
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#5
Looks great!

Congrats on the new release.

When are you going to list it and when do you expect to ship?
 

Michael Kelly

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#6
The plan is to have them ready for limited production by the end of May. We also made a change to add a BNC output. To do this we had to move the speed LED's to the side of the board. Here are a couple of 3D captures of the final revision:

pi2aes_top_p2.PNG


pi2aes_front_p2.PNG
 

headshake

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#7
Any power supply recommendations for this hat?

When are you gonna start taking cash?

I'm still interested in this puppy.
 

Michael Kelly

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#8
Prototypes are complete and testing has gone very well. We have bought enough parts to build an initial 25 units. Price will be $129 w/o case, acrylic case (like our 502DAC Case) will be $15. As for power supply we will offer a basic [email protected] switching supply, but you can get your own if you want.

Michael
 
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#11
@Michael Kelly Have you compared the new hat to your old when it comes to sound quality?

I saw on another forum that you have a digione sig.. Have you compared the pi2aes to that?

The last question, I also see you are gonna sell a few next tues. Will you have power and the cases too?
 
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