PI2AES Digital Audio Shield for the Raspberry PI

[Michael Kelly]

Ah thank you!

Also, out of curiosity how come the board uses a 24v psu? It makes it quite difficult to find a linear psu for it (only one I can find is the £330 s booster). Can't even use something like the Ifi Ipower with it

Was looking at getting a linear psu for the pi itself but not sure how much benefit there would be if I can't also get a good psu for the hat

24V was used to allow add on boards to support analog output. It also allows the main 5V converter to run much more efficiently than if it was 12V.

As for supporting a linear, that is a complete waste of money IMHO. There’s a number of very good threads on SBAF that document folks experience with powering the unit with a linear, and also using split power between the PI2AES and the raspberry pi. So far there has been very little evidence to conclude that a linear improves the sound. It certainly does not improve the measurements. The ones posting on our website we’re done with a switching power supply, albeit a good one mind you from Meanwell.

 

[GoldenOne]

24V was used to allow add on boards to support analog output. It also allows the main 5V converter to run much more efficiently than if it was 12V.

As for supporting a linear, that is a complete waste of money IMHO. There’s a number of very good threads on SBAF that document folks experience with powering the unit with a linear, and also using split power between the PI2AES and the raspberry pi. So far there has been very little evidence to conclude that a linear improves the sound. It certainly does not improve the measurements. The ones posting on our website we’re done with a switching power supply, albeit a good one mind you from Meanwell.

Ah that makes sense.

Wasn't in any way a criticism, just was curious what the reasoning behind it was. Very excited to receive mine!

Also out of curiosity, if I were to power the pi separately, and use only the i2s output, would the onboard 5v switching supply actually be powering anything/active?

 

[Michael Kelly]

Ah that makes sense.

Wasn't in any way a criticism, just was curious what the reasoning behind it was. Very excited to receive mine!

Also out of curiosity, if I were to power the pi separately, and use only the i2s output, would the onboard 5v switching supply actually be powering anything/active?

Yes, all of the PI2AES is powered from that supply. The Pi power is routed through a jumper so it can be provided from the PI2AES or the Pi's own power input. Removing the jumper is not strictly required as there is a circuit that insure no harm. But if you're after reducing noise (such as it is) by powering them separately then removing the jumper is best.

 

[Reddy]

Of course it would be good if the PI2AES would not benefit from an extreme smooth supply.
According to your experience, does it make a difference which Raspberry PI 2, 3 or 4 is being used in order to archive as less jitter as possibile?
I will soon get a DAC with coax aes and HDMI i2s input. Which one of the three inputs do you recommend?

 

[Michael Kelly]

Of course it would be good if the PI2AES would not benefit from an extreme smooth supply.
According to your experience, does it make a difference which Raspberry PI 2, 3 or 4 is being used in order to archive as less jitter as possibile?
I will soon get a DAC with coax aes and HDMI i2s input. Which one of the three inputs do you recommend?

For audio there seems to be no obvious sound quality benefit to any one Pi. But, I personally would get the Pi 4 w/2GB as it is the most bang for the buck and gives you more computing power for other tasks. Running an audio app does not create heat issues, but other, more intensive multimedia tasks might.

As for DAC input, I2S over HDMI would give the lowest jitter. But, depending on the DAC you may find no discernible sound quality benefit over AES Balanced (XLR), AES Coax (BNC) or SPDIF (RCA). However I do know the optical is definitely higher jitter (though again, not necessarily better sound).

 

[Michael Kelly]

Assembly instructions for the 7"Display case are now on line. Since we've already shipped a few dozen, it was clearly time to get his done! For some reason even with all the extra time Covid has provided, I still wait until the last minute!

http://www.pi2design.com/uploads/4/8/5/3/48531975/pi2aes_7_display_case_assembly.pdf

Feedback welcome as this is the first draft.​

 

[DaaDaa]

anyone here using this + pi3 as a streamer?

 

[DonH56]

Assembly instructions for the 7"Display case are now on line. Since we've already shipped a few dozen, it was clearly time to get his done! For some reason even with all the extra time Covid has provided, I still wait until the last minute!​

​

http://www.pi2design.com/uploads/4/8/5/3/48531975/pi2aes_7_display_case_assembly.pdf​

​

Feedback welcome as this is the first draft.​

Now someone needs to write a program to turn the display into a couple of Vu meters...

 

[somebodyelse]

Now someone needs to write a program to turn the display into a couple of Vu meters...

Something like this? Image pinched from this post about picoreplayer.

 

[sevenper]

I sent a unit to Amir and for some reason it had issues. He sent it back, but I have not yet sent him another unit. We have been having trouble keeping them in stock. It’s taking awhile to ramp up full production. Hopefully soon.

Hi Michael. Finally,
Did you send another unit for testing? was there a review?

 

[Michael Kelly]

Hi Michael. Finally,
Did you send another unit for testing? was there a review?

I did not. We are still about 3-4 weeks behind current orders, and more come every day. I know, I know, there are much worse problems these days!

 

[DaaDaa]

I did not. We are still about 3-4 weeks behind current orders, and more come every day. I know, I know, there are much worse problems these days!

Hi Michael. the pi2design website displays a little pop up every time a sale has occurred similar to the other cookie cutter webstores. These pop ups are constantly looped and usually show the newest ones, but the ones on your store keeps showing the same ones from 2 to 3 months ago so please look into that. maybe some settings need to be adjusted to reflect these numerous sales. i have also been trying to find a few people who are actively using it to ask them for reviews and impressions but i cant find any on here or on headfi. so please ask some of your customers to share their experience with us.

 

[Michael Kelly]

Hi Michael. the pi2design website displays a little pop up every time a sale has occurred similar to the other cookie cutter webstores. These pop ups are constantly looped and usually show the newest ones, but the ones on your store keeps showing the same ones from 2 to 3 months ago so please look into that. maybe some settings need to be adjusted to reflect these numerous sales. i have also been trying to find a few people who are actively using it to ask them for reviews and impressions but i cant find any on here or on headfi. so please ask some of your customers to share their experience with us.

I truly have no idea how to fix that. But I will look at either fixing it or shutting it off, so thanks for that.

Almost all of the activity surrounding our board has taken place on super best audio friends. It’s the forum that we announced the products as they’ve come out and where a large number of our customers have come from. There are several threads where folks talk about using our board with their particular flavor of DAC. I had a couple of customers post on ASR about their experience, but since they were not coming with a large number of measurements, the crowd here was pretty unfriendly. As an engineer I’m perfectly fine with using measurements to provide a metric for comparing between various products, but I think most can agree that at the end of the day it is about how it sounds to you personally.

 

[DaaDaa]

I have a question about the acrylic case. my unit originally was with pi3, i just swapped it for a pi4 and it doesnt fit right. of course this didnt surprise me since the pi 4 and pi3 are not identical and the ethernet port usb hdmi etc are different. but on your site there is only one acrylic case offered and it clearly states that it supports pi3 , and pi4. so im a little confused as to if i buy another case will it be the same or different? is there a newer version that supports both?

btw an absolute joy to use. great product and rock solid in reliability so far. well done.

 

[Michael Kelly]

I have a question about the acrylic case. my unit originally was with pi3, i just swapped it for a pi4 and it doesnt fit right. of course this didnt surprise me since the pi 4 and pi3 are not identical and the ethernet port usb hdmi etc are different. but on your site there is only one acrylic case offered and it clearly states that it supports pi3 , and pi4. so im a little confused as to if i buy another case will it be the same or different? is there a newer version that supports both?

btw an absolute joy to use. great product and rock solid in reliability so far. well done.

Contact us ([email protected]) and we'll see about getting you a new case with Pi 4 support. No charge, just shipping.

 

[DaaDaa]

Contact us ([email protected]) and we'll see about getting you a new case with Pi 4 support. No charge, just shipping.

thank you for the kind offer. I emailed support.

 

[navin]

Separate Ultra low noise LDO's for WM8804 and NDK Clocks

Hi Michael,

I stumbled on to this thread while trying to Google if I can use the PiAES as a HAT with Allo's USBridge Signature. Can the Pi2AEs be used with the USBridge Signature?

Would this then give me USB out (from the USBridge's USB CLEAN OUT), and SPDIF COAX/OPTICAL, AES BNC/BALANCED XLR OUTPUT from the PIAES board?

Lastly, I could not find any HDMI port (LVDS/I2S) for the DS2063 Differential Transmitter. Is that included on the board?

Power would be provided from a regulated linear power supply with 24Vdc at 3A for the Pi2AES and 5.2V 5A for the USBridge Signature.

I would like to know your thoughts about Volumio, Moode, Max2Play etc well as to which is more reliable especially when the USBridge is reading from a self powered USB Hard Drive (LaCie D2 Professional).

Thanks.

 

[Michael Kelly]

The HW reference manual on our web site will answer these questions.

 

[navin]

The HW reference manual on our web site will answer these questions.

Sir, I did read the manual before posting. This is what I understand from the HW manual.

1. The Pi2AES takes the I2S signal from an RPi and produces SPDIF Coax, SPDIF Optical, 75 ohm BNC, and Balanced XLR outputs. It does not specify if the existing USB out on the USBridge Signature would still function.

2. I see an HDMI port (labelled I2S over HDMI) next to the DC input jack (and I saw an HDMI port in the Block Diagram on Page 7 of the HW manual). I did not want to assume that I could use this HDMI (I2S LVDS) to directly connect to the I2S LVDS input of a DAC (Gustard). However, after reading page 9 of your "display case assembly" instructions I got clarity on this. PI2AES 7 Display Case Assembly.docx (pi2design.com)

3. I know the Pi2AES can power an RPi via jumper W2 (page 12 of the HW manual) but I am not sure if the same can power a USBridge Signature.

And lastly, I have read so many differing opinions about Volumio, Moode, Max2Play etc. that I was completely confused. I am not PC or software literate (I graduate college before the PC was invented) so was hoping to get some closure on which software is most reliable especially when accessing a USB Hard drive.

Sorry, I did not mean to offend or ask "stupid" questions.

Thank you.

 

[Michael Kelly]

I am not offended at all! I am glad you read the manual and I can clarify the last few points.

1. The PI2AES has no impact on the functionality of the Raspberry Pi it is attached to. I would guess the same is true for the Allo device.

2. The I2S over HDMI is LVDS and supports the Gustard Pinout directly. All you need is a standard HDMI cable. Just keep it short (1-3Meters) and you'll be good.

3. The PI2AES provide 5V@4A to the Raspberry Pi GPIO header. You will need to refer to the Allo docs to find out if thjis is sufficient. it is my understand that the USBBridge behaves like a standard Pi so you should be fine.

As for software, that is not something we can advise on. I suggest asking that on the forums the software vendors maintain.