[SOLVED] Allo Asix driver related SQ

[marcinmarcin]

Hi, recently moved from 8.3.0 64bit to 8.3.3 64bit (clean instalation on fresh card with Raspbery Imager).

System: usbridge signature + dac USB
Settings: the same both systems - direct hw, disabled software volume (null), upnp enabled and 16mb cache

On 830 with mconnect player sound is really great - I think best what I achieved with usbridge signature.

But unfortunately with 833 something happend with quality - it still plays without crackles (like on other systems without Asix driver) but sound become a little more harsh and unpleasant - form me little worse than 830... then I saw that 830 was last version with Allo Asix driver... maybe this is related?

Is it possible to still have asix driver for future versions/updates? Or to install it manually? Difference is quite noticeable, and I would like to stay with moode and its updates in future, but with 830 quality.

Thank you @Tim Curtis for your efforts

[Tim Curtis]

AFAIK Allo's modifications to the stock ASIX driver were only to bump the data rate a bit so that DSD512 bitrates could work. The stock driver was already good for up to DSD256.

We reverted to the stock ASIX driver starting with moOde 8.3.1 because the Allo modified driver sources would not compile under the 6.1 kernel in 8.3.1 and since Allo stopped maintaining their modified driver around mid-2022 (http://3.230.113.73:9011/Allocom/USBridgeSig/) no tech resources are available from them for debugging.

Some historical things about the Allo modified driver from a few years back.

1. ASIX would not incorporate the Allo changes into their stock driver.
2. Raspberry Pi Linux devs would not accept the Allo driver into the kernel unless it was submitted by the driver manufacturer (ASIX)

If someone takes on responsibility for fixing and doing ongoing maintenance for the driver we could consider including it again. Our build script for the Allo driver is in our package repo https://github.com/moode-player/pkgbuild...9/build.sh

It's entirely possible though that the current stock ASIX driver already supports the higher data rate for DSD512 thus eliminating the need for Allo modified driver. I don't have any DSD512 files and so not able to test.

[marcinmarcin]

Thank you for such detailed explanation. Now I can understand all your moves with replacing driver. Allo is generally not visible from last year... shame, because they had a few great sounding products. Maybe sound difference is because of new kernel. On Volumio one plugin (musis services shield) with process/core priority/setup was making some serious changes in SQ.

Some adviceses for improving SQ?

[Tim Curtis]

For sure the loss of Allo is a huge loss for everyone because it means fewer choices overall and in particular, fewer choices  in the I2S HAT space.

As far as sound quality goes, thats a personal preference and can be heavily influenced by all sorts of mind biases and expectations, hearing range, etc and especially suggestions that this or that software tweak will "improve" the sound.

Keep in mind that audio player softwares like MPD, ALSA, CamillaDSP etc are multi-threaded designs that expect the OS to automatically schedule and prioritize their worker threads across multiple CPU cores as it does for everything else running on the system. This works perfectly because the Linux task scheduler is a piece of AI thats prolly the most heavily optimized and refined parts of the OS kernel.

When you mess with it your mind may be calmed but in reality your system ends up running in an abnormal and degraded state.

[marcinmarcin]

Agree, playing with some "tweaks" was making rsome strange sound changes. My idea was rather that some changes related to core usage/task priorities could seriously impact SQ (rather in negative way).

[marcinmarcin]

@Tim Curtis made a fresh install for both 830 and 833 on two SD cards. Compared them. 833 is OK. There is no need to revert back to old Allo driver. You can close.. I dont see this option...

EDIT: solved

[marcinmarcin]

Thank You, for your feedback, and explanation

[marcinmarcin]

@Tim Curtis is there a chance to add Asix driver to 32bit moOde? 64bit version works ok - no pops/cracks until 24/96b. With 192 once per 30s I can hear it. Not a problem at all - workaround is to listen Qobuz limited to 24/96.

But 32bit version of 8.3.6 has squirks (related probably to unfortunate ASIX) every 15/20 sec. The same what happens on OS without Asix driver...

[Tim Curtis]

Very odd about the audio glitches. I don't recall experiencing this on my SIG but in any case I'll get it out of storage and run some tests later today or tomorrow.

The stock ASIX driver is part of the Linux kernel and so it exists on both 32 and 64 bit kernels.

[marcinmarcin]

Just checked freshly installed 830 32b with Qobuz 24/192 by Mconnect/UPNP. Works great - totally no cracks... (15min of critical listeniing and no pops)
Are there any security issues with using older version?
It seems that with this old hardware, old linux kernel with allo asix works best