Rpi & I2S via HDMI - Printable Version

Rpi & I2S via HDMI - Printable Version

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Rpi & I2S via HDMI - Woodroww - 07-27-2021

Hi,

I see more and more DAC's with a I2S input, where they use a HDMI connector.

I wonder how you could get this kind of signal from a Pi?

Did see re-clockers etc, but I have to admit that I am at loss.

I am from the SPDIF coax and Toslink era...

Kind Regards

Woody.

RE: Rpi & I2S via HDMI - TheOldPresbyope - 07-27-2021

(07-27-2021, 09:07 PM)Woodroww Wrote: Hi,

I see more and more DAC's with a I2S input, where they use a HDMI connector.

I wonder how you could get this kind of signal from a Pi?

Did see re-clockers etc, but I have to admit that I am at loss.

I am from the SPDIF coax and Toslink era...

Kind Regards

Woody.

<Full disclosure: I believe the notion that an I2S-over-HDMI interface is sonically better is classic snake oil. See, for example, Study: is I2S interface better....>

The RPi doesn't have an I2S-over-HDMI interface so you'll need an I2S-to-HDMI HAT of some sort. Such things exist but I have no experience with them.

As well, it would seem you'll need some sort of I2S driver for it which can communicate the capabilities of the DAC on the far end of the HDMI cable to ALSA (and hence to moOde).

Perhaps another moOde user can add more information but I'd suggest you try the diyaudio.com forums where you're likely to find actual users of this technology.

Regards,
Kent

RE: Rpi & I2S via HDMI - yannig - 07-28-2021

since the RPi doesn't have an I2S-over-HDMI interface, it is possible to use this kind of board :

https://www.audiophonics.fr/en/dac-and-interfaces-for-raspberry-pi/ak4118-digital-interface-spdif-i2s-hdmi-lvds-raspberry-pi-3-pi-4-p-14255.html

RE: Rpi & I2S via HDMI - Woodroww - 07-30-2021

Hi yannig,

Many thanks for this link! Will order it. I guess, just as TheOldPresbyope said, that I2S via HDMI may be just a hype. But it's good to try it out & hear for myself.

Regards,

W.

RE: Rpi & I2S via HDMI - DRONE7 - 07-30-2021

(07-30-2021, 09:08 PM)Woodroww Wrote: Hi yannig,

Many thanks for this link! Will order it. I guess, just as TheOldPresbyope said, that I2S via HDMI may be just a hype. But it's good to try it out & hear for myself.

Regards,

W.

Do look carefully at the filetype and playback rates for this board...via HDMI the DSD rates are less than for most i2s HATs and USB connected DACs
seems to be tied to the SPDIF rates for the other outputs

Quote:supported sampling frequencies
PCM: 44.1-384kHz (moode)
PCM: 44.1-192kHz (Volumio)

DSD DSD64 - DSD 128 (moode)
DSD: DSD64 (Volumio)

even a cheapie ESS 9028 dac does DSD256 and a 9038 even more.
https://www.ebay.com/itm/233438827803?_trkparms=aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D233610%26meid%3Dc7d4f6a7ce30410492bdad3c9ddb0b44%26pid%3D101195%26rk%3D1%26rkt%3D12%26sd%3D233440089648%26itm%3D233438827803%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv9PairwiseWithPLXWeb%26brand%3DUnbranded&_trksid=p2047675.c101195.m1851&amdata=cksum%3A233438827803c7d4f6a7ce30410492bdad3c9ddb0b44%7Cenc%3AAQAGAAACAKhPKRFejWZxnwqfHevpl7PhhAAdDskRIwKqHb9Q1zK02Ief3Ql2IY6jLwkqIx6j5mIwBG6sRXy0jtyq5XJOnjz%252FJJs9vfhpFDcpf5bjQe9FcCRnGBdWg9i0NoxG6RW9OdaTERWPpgXrT0U7496DOVr6W0BCUuXI89aXkIwmxWuysGQcmvtCwWxwcNtmyCusMpc5ngM7VSwIOj79DiWIq6FirCFwWuLV3lwGWBCjec1h%252FyZiihJLi4ZpvTtuNHkjXwltLLz0zFls4gTW68JiA2gjTB1Rqbyy79vluyyEvkNQpQeNuyaTNE5LHJajLCUb%252Bmn97NxoFbZci%252BdUdXACYFRSuym4h4asyIjJhMFIDvHSCa%252FgpF4Pn69ucYEBWB5zVW4iV94%252BS8qkuCMyE2VeBJMUqtyKhosWVndPEYxADPD67zT2PlLTwrvcwJ25XfAEDcRE%252BQSAhfFwdgQO69rgf36p83hUk1zr0Itu0ZhG3g1N69xeffOnXoG0VblDf7aLvN5qlxtYGbM%252BUaHpmANvKrxIZfVJbC%252F%252BG3iizA8jyVLRLwncbTWbIcabs5p82OpfpBpMLVl4wDyORccx9HqL9u3qnPinHGH4cg6ga8E73H8zA6FcuAA9t%252ByMKUAhY4EK1TTPholVdvqTFFZx9g3JUsSwAMArG6rYpg7N0m2rt5c3%7Campid%3APL_CLK%7Cclp%3A2047675

RE: Rpi & I2S via HDMI - Tim Curtis - 07-30-2021

I2S interface max bitrate is 384K so limited to DSD128 and I2S can only do DoP and not native DSD. You'll need USB interface to do higher rates (> DSD128) and native DSD.

RE: Rpi & I2S via HDMI - DRONE7 - 07-31-2021

Or an up-sampler such as the AK4137 (available as either stand alone board or an i2s hat for the Pi) to feed above DSD128 to a capable DAC.

RE: Rpi & I2S via HDMI - Woodroww - 08-01-2021

(07-30-2021, 11:32 PM)Tim Curtis Wrote: I2S interface max bitrate is 384K so limited to DSD128 and I2S can only do DoP and not native DSD. You'll need USB interface to do higher rates (> DSD128) and native DSD.

Thanks for this info. Seems that there is no need for I2S when you have both SPDIF and USB available. Not to open a can of worms, but about as useful as MQA [Image: biggrin.png]