Thesycon DSD workaround ?

[TheOldPresbyope]

In the latest moOde 7.6.0 update we see

Updated WIP release notes.

- Bump to MPD 0.23.4 with new DSD option "thesycon_dsd_workaround"

One might reasonably ask oneself: Self, what the heck is this workaround and why do I need it?

Here's some lines I found in the MPD source code repo

Code:

  * - **thesycon_dsd_workaround yes|no**
    - If enabled, enables a workaround for a bug in Thesycon USB
      audio receivers.  On these devices, playing DSD512 or PCM
      causes all subsequent attempts to play other DSD rates to fail,
      which can be fixed by briefly playing PCM at 44.1 kHz.

which is part of commit #3413b1ae, Nov 4, 2021. The commit doesn't reference any issue and I couldn't find one quickly searching on 'Thesycon' or 'DSD'.

Pardon my ignorance but I thought Thesycon specialized in driver toolkits for Windows systems. Does anyone know of a "Thesycon USB audio receiver" which displays the symptom described?

Regards,
Kent

[MikeyFresh]

In the latest moOde 7.6.0 update we see

Updated WIP release notes.

- Bump to MPD 0.23.4 with new DSD option "thesycon_dsd_workaround"

One might reasonably ask oneself: Self, what the heck is this workaround and why do I need it?

Here's some lines I found in the MPD source code repo

Code:

  * - **thesycon_dsd_workaround yes|no**
    - If enabled, enables a workaround for a bug in Thesycon USB
      audio receivers.  On these devices, playing DSD512 or PCM
      causes all subsequent attempts to play other DSD rates to fail,
      which can be fixed by briefly playing PCM at 44.1 kHz.

which is part of commit #3413b1ae, Nov 4, 2021. The commit doesn't reference any issue and I couldn't find one quickly searching on 'Thesycon' or 'DSD'.

Pardon my ignorance but I thought Thesycon specialized in driver toolkits for Windows systems. Does anyone know of a "Thesycon USB audio receiver" which displays the symptom described?

Regards,
Kent

That's always been my understanding as well, not only have I not had any problems with DSD and Moode using various different DACs, but I've only ever heard of Thesycon in the context of Windows drivers, and never as any sort of "USB audio receiver" which sounds like hardware of some sort but perhaps that's just a poor wording of the description.

[Tim Curtis]

According to their website they provide among other things USB receiver firmware.
https://www.thesycon.de/eng/home.shtml

[TheOldPresbyope]

Interesting. I missed that.

I have only one DSD-capable DAC, the original Khadas Tone Board. I suppose it could have Thesycon code in the XMOS XU208 firmware but the only reference on the Khadas website and file repository is to using the Thesycon driver in Windows. 

Like @MikeyFresh I have not had any problems dealing with moOde and this DAC playing either DSD or PCM material.

I'll have to try enabling the workaround to see/hear what happens

Regards,
Kent

[MikeyFresh]

Interesting. I missed that.

I have only one DSD-capable DAC, the original Khadas Tone Board. I suppose it could have Thesycon code in the XMOS XU208 firmware but the only reference on the Khadas website and file repository is to using the Thesycon driver in Windows. 

Like @MikeyFresh I have not had any problems dealing with moOde and this DAC playing either DSD or PCM material.

I'll have to try enabling the workaround to see/hear what happens

Regards,
Kent

Almost all of my DACs use the XMOS USB input boards, and I'd always thought those all used XMOS firmware too, but perhaps that was just an incorrect assumption on my part.

Of my DACs the only two that use something other than the XMOS USB input are the Resonessence Labs Herus, which has a Cypress Semiconductor USB input said to be running custom Resonessence Labs firmware, and the ADL Stride, which uses a Tenor te7022L USB input and is thus not UAC2 compliant.

The Herus has no problem with Moode and DSD up to DSD128, or PCM up to 352.8kHz. The Herus does use the Thesycon Windows driver, so now I'm curious if that "custom firmware" might actually be Thesycon.

[TheOldPresbyope]

Come to think of it, my Khadas Tone 1 board specs include the line item

Sample Rate: PCM: Up to 384KHz @ 32bit          DSD: Up to DSD256 @ 1bit

This means it is unsuitable for testing the edge case "playing DSD512 or PCM".

Regards
Kent