Low Level Crackling - Clock issues?

Swapped out my Topping D10s DAC (audio path = Roon on M1 Mac Mini, files on Synology DS 918+, endpoint = Raspberry Pi 4 running RoPieee (latest version) which is then hooked up to the DAC) for a Focusrite Scarlett 18i20

The Topping was perfect apart from not having headphone output so as I’ve had the Scarlett spare, I’ve popped it in place hooked up via USB (A on the RasPi to C on the Scarlett), but I get really low level crackling, like ultra-low vinyl crackle.

I’ve tried USB 2 and 3 outs from the RasPi, but both are the same. Clock is set to internal on Scarlett.

Is this with 2-channel or multichannel with your 18i20?

If multichannel - this is a known issue with Linux + Focusrite (and a whole host of pro audio interfaces)

Someone has a Linux patch and plans to bring it to mainline Linux kernel

Focusrite Scarlett Gen 3 4i4 (and others) - LinuxMusicians

Focusrite Scarlett 2nd and 3rd Gen mixer driver - LinuxMusicians

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Just 2 channel. Connected to my Neumann KH750/KH80 setup.

I think it’s a problem regardless of 2 channel or multichannel

See the threads I’ve linked above which include 2-channel Scarlett models…

Shame - really spoils some of my fav tracks by Nils Frahm etc. I suppose there’s a reason why Focusrite Scarlett is cheap. My RME ADI2 DAC is fine in another listening location. Might have to get rid of the Scarlett.

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Don’t know if it’s related, but had faint irregular tick sounds after a certain Ropieee update about half a year ago with wireless and wired connections, which Harry couldn’t reproduce.
Switched to DiePi with Roon bridge and problem was gone on both RPi3b+and RPi4b connecting via USB to a SMSL M300Mk2.

Give it a shot with Diet-Pi and see if it goes away, nothing to lose really!

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Good info both - thanks muchly. I’ll have a go with DietPi and also others if no joy - it’s only the time to re-flash a card I suppose. Trouble with intermittent faults is that developers are really pushed to get to the bottom of a solution.

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Yeah I have the 18i20 Gen3 and also have ADI-2.

RME is the exception not the rule when it comes to Linux support (proper UAC2 support even though they all say they support UAC2 which should include Linux).

That forum I linked has all the woes of many models. Just search for crackling.

I’ve had latest Tascams, Focusrites, Universal Audio, Audient models and same issues.

But my own failed experiences with those are with multichannel mode, not stereo.

Latest Motu seems to be good when you pair it with latest Linux kernels, like v5.11 , from user reports.

If you have the ability to demo a Motu UltraLite Mk5 risk free, give it a try.

Or just get another RME if you only need stereo and be done with the Linux woes forever.

Interesting you mention MotU - I’ve got an M4 in transit from Thomann as we speak. Can’t get hold of an Ultralite Mk5 for months it seems. Also got a lovely old 828 Mk2, but it’s FW800 input just isn’t practical to use in the same way.
Multichannel isn’t something that’s of great importance just now but it’d be good to have enough outs on an interface for future proofing.

If they share the same USB interface then it should be fine. I guess you’ll find out and can confirm.

@grizaudio does your UltraLite Mk5 play nice with latest RoPieee version?

I see RoPieee is running kernel v5.10 - is that new enough for you?

The latest kernel appears to be 5.10 for RoPieee 4.002.

I’ll post back the results for the M4 when it arrives.

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Thanks that would be great. Especially when I try to help people with recommendations (or for myself) , it’s nice to slowly grow the list of recommendations.

And what to avoid lol.

Note my comments are purely to do with Linux.

Focusrite and those other pro audio names I mentioned are rock solid with Windows and macOS in my experiences. They all officially support these 2 operating systems.

Absolutely - I get your drift :wink:

The worldwide chip shortage is a pain at the moment though for the purchasers of interfaces and DACs. I’ve had the M4 on order for 2 months and I see that the new ADI2 DACs have adopted new chips due to AK being unavailable.

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Quick update after giving Balena a workout tonight:

RoPieee - clicking
DietPi - no go
VitOS - clicking
Volumio - lots of clicking

Back to the inky darkness of the RME ADI2-DAC then for the time being for me, until Harry updates the kernel (if that helps - who knows??).

No Ropieee didn’t work for me. Ubtuntu server installed with Roon bridge works perfectly.
Ropieee is designed for stereo use only.

Send Harry a message directly and ask.

Do 4 channel interfaces work with Roon?
This thread seems to indicate Roon doesn’t work with 4 channel devices.

I would suspect multichannel support for all Ropieee functions could be tricky.
I could be wrong.

He only needs stereo but still an issue with Linux and many pro audio interfaces as discussed above

Ok, I could test stereo, if thats helpful.

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I just did some quick testing.

With sampling set at say 96, or 192, I get clock sync, but music will not play.
With no sampling conversion, and 2.0 set, downmix, Roon plays, but I get no sync or music.

It doesn’t play anything with Ropieee.

My advice install Ubuntu, and install the options you need.

I also have an RME ADI2 dac FS, which works perfectly…

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Some more things @Michael_Contini-Hill can try when his Motu M4 arrives