896 mk3 hybrid crackling noises

[buddyrich]

I just started using a new AMD Ryzen PC with windows 10 and cubase 10.5. I'm using a MOTU 896 mk3 USB. When I have a session running in cubase, I randomly get crackling and glitching noises and audio dropouts. This can occur as soon as the session opens or at any random time while working in cubase. It's most likely to occur (I'd say 95% of the time) when adjusting the audio buffer size. Regardless of whether I'm increasing or reducing buffer size, the problem is certain to occur. My CPU meter is never over halfway and that's only in large sessions. PC has 32Gb of ram so that isn't the problem. This problem happens even in small sessions with few tracks and no plugins.

I have a Microbook II which I tried with the system and works fine. It uses the same drivers as the mk3 and they are up to date. Also, the firmware on the mk3 is up to date: v1.02.

I've gone through everything I can think of, used different cables etc. Auto updates disabled, power settings in USB root hub changed. I am running an NVIDIA card but hope this wont be the problem. The fact that the Microbook runs successfully suggests to me that the graphics cards isn't the problem. I have a ticket open. If USB is a problem, I'm considering going down the firewire route, given that this unit is a hybrid.

Can anyone suggest any possible cause or solution?

Thanks

[mikehalloran]

The most obvious possibility:

[buddyrich]

Could you elaborate on that a bit? I have the master clock set to Internal in cubase. That's pretty much the limit of my knowledge of clock settings. I'm also using an 8pre, connected to the mk3 via ADAT.

[mikehalloran]

You are assuming that all 3 sync to the same clock. Are they? Searchable pdf files are your friend here.

Setting buffers is different on Windows, if I recall. That can still be your issue.

[HCMarkus]

Could you elaborate on that a bit? I have the master clock set to Internal in cubase. That's pretty much the limit of my knowledge of clock settings. I'm also using an 8pre, connected to the mk3 via ADAT.

Where is that 8Pre getting its clock? It should probably be set to sync to its ADAT IN port, which means there needs to be an optical cable running both to and from it connected to the mk3. As MIke noted, the manuals are your pals.

[buddyrich]

Ah, I get it now. I will remedy that and try again. Thanks!

[buddyrich]

I disconnected the 8pre completely and disabled all optical connections on the mk3. Same problem. Oddly, it occurs much more frequently when changing buffer size upwards. At 192 samples things generally run fine with no latency and the PC can handle it. Perfect for tracking. When I increase buffer size in order to mix for example, it goes crazy with lots of nasty noises. If I change from 192 to 2048, it almost always happens. However, it has happened on every buffer setting. Sometimes it's happening as I boot cubase, sometimes it doesn't happen at all (although not very often).

To recap: The mk3 is in standalone mode with no other unit connected to it, the optical ins and outs are disabled, the unit is connected to the computer via a working USB2 cable (I have tried other cables with the same result) plugged into the USB2 port on the PC. Master clock is set to Internal. The mk3 is running 88.2 and the cubase session is at 88.2. When the noises aren't happening, audio playback is normal and things sound fine. Windows update is disabled and power saving is turned off on USB root hubs. The only other device connected to the PC is a powered USB-C hub which has eLicenser, iLok and keyboard/mouse dongles connected to it. I managed to get the session to run without these connected but the problem still occurred (on boot this time and during subsequent adjustment of buffer setting).

Is there anything else that could be the cause?

[CharlzS]

Sounds like maybe something in the background competing for attention. If you use the MOTU device for system sound, make sure everything in the Sound Control Panel is set to the same sample rate (advanced tab for each output pair) as your DAW session. Configuring Windows for 'No Sounds' helps. Check any other apps that may be accessing the device in the background including MS Store apps. Also check to make sure the device is set to internal clock. Easiest is not to use MOTU device for system sound.