DSD with Pi2AES over I2s

Hi all,

I ran into an issue after just setting up my new Pi2aes. I am using I2s which I believe should support up to dsd 512 and I believe up to pcm 768 with my dac. I cannot up sample at all in Roon. I am thinking it is because Rooieee Is seeing the device has a Hifiberry and only is supporting up to 192 PCM. Am I mistaken? Can this be added to allow for support with this device over by I2s?


Looking at the online manual (http://www.pi2design.com/uploads/4/8/5/3/48531975/pi2aes_hw_ref_manual_p3_3.pdf), I see nothing to suggest this device does anything more than 192k. In fact, the block diagram shows the i2s signal coming out and feeding both the i2s ports and the subsequent conversion to AES/SPDIF. All the i2s ports are doing is getting you the separate clock and data signals before they are merged into the combined clock+data that is SPDIF.

Put another way, there is only a single clock input to the WM8804 that outputs both the i2S and the SPDIF feed.

I don’t believe that is correct, it’s coming directly off the Pi I2s. Believe it should support dsd. The pi does over usb.

Please look at their published block diagram. The I2S our to the ports is coming off the WM8804.

I did maybe you’re looking at the wrong diagram. Please look again. Thank you

The WM8804 is listed as the master, the I2S on the GPIO is slave. RoonBridge on RoPieee is reporting what the ALSA device enumerates itself as. Has pi2design published a custom kernel patch for Linux?

Probably best you contact pi2design for confirmation.

They don’t. Ropieee Supports DSD over USB I would hope that It could be enabled to support this device over I2s.

Again, it’s Roon Bridge enumerating the ALSA devices as reported by the kernel. While RoPieee’s creator does do custom kernel builds to add new USB device identification before it gets approved in uostream, they are not creating custom kernel code themselves. They are just adding USB VendorID+ProductID codes for XMOS-based devices using a custom VID+PID. And that just affects the recognition of native DSD for DSD512. PCM identification isn’t even part of that.

As @cwichura explained, Pi2AES is a strictly PCM device. The I2S outputs are just the appropriate encodings for the PCM output from the WM8804. Ropieee allows you to set the audio HAT to “Pi 2 Design Pi2AES”. Roon reports the maximum sample rate as 192k PCM. That’s what the hardware supports.

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It passes the I2s from the raspberry pi. Yes I read what he said thank you

Hi, also it seems DSD is only possible via DoP…does anyone know of a solution which enables DSD512 I2S output to a DAC? Or even DSD256?