Audio glitching when used alongside audio interface on mac aggregate device

Hi, my first post here!

I’ve had a witch a few months now, and mostly just been using it with modular gear, uploading patches as and when I need via USB, and switching between them. I recently added it to my aggregate device on my macbook, thinking that it’d be a nice option to be able to send / receive straight from or to it without going through the mixer and using another audio channel on my iConnectivity ICA4+. But if the witch is on, and enable in the aggregate device, the audio inputs and outputs on the whole system start glitching and stuttering. I only noticed on Friday after the system had slept and then I reconnected the audio devices manually, after which no matter on the reset of the system, or stopping and starting coreaudio would the system behave itself unless I either unplug or disable the witch in the aggregate device. I guess it’s no great loss, but I would like to solve it if possible; sending and receiving from it would be useful mostly with virtual modular, or even just when playing some of the nice generators it has…



I’m not an expert in MacOS audio subsystem, but I would guess that aggregate device would need a longer buffer than a single audio interface. So you may try tweaking that or some other settings to see if they make any difference.

There should be some improvements to USB audio in the upcoming OpenWare release (as they’ve just released a dedicated OWL powered audio interface), but I’m not sure if your issues will (or even can) be fixed on OWL side.

Hmm interesting, thank you that’s good to know about. I did try a few buffer settings to no avail before posting here, I’m surprised I never noticed it earlier - but perhaps I’d not played through the interface while the witch was actually on; I’d been unplugging it regularly as I didn’t like seeing it powered while I wasn’t actually using it. I’ll look out for the new openware, I’ve not explored that side of it at all yet…



I have tested agregated devices in MacOS with firmware 22.4 and 22.5 and works like a charm!
Try updating your witch:

Oh splendid, I will, thanks!

Hmm I found my way to the uploader site but on trying to do the deed, I get this

  • Reading file Witch 22.5 rc1.syx
  • Sending data 345242 bytes
  • Error: Error 0x60 Invalid bootloader
  • Error: Error 0x60 Invalid bootloader
  • Error: Error 0x60 Invalid bootloader
  • Error: Error 0x60 Invalid bootloader

I have to then reset to bootloader, then reset the device and I’m back where I started - is it because I’ve already got lots of patches installed maybe and the memory is full?

IIRC, that error message is what you get if you try to flash firmware without resetting to bootloader mode first.

Ah, nice one, I should have realised that - I’m tempted to write a short tutorial for those that follow in my dopey steps :slight_smile:

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A brief guide on how to upgrade / flash firmware - I did this on my Witch, took me a few goes and a bit of guidance from the above contributors to achieve…

a. get firmware sysex from here: Releases · RebelTechnology/OpenWare · GitHub

b. go here: OpenWareLaboratory

c. make sure your device is connected and showing as such

d. select / set the sysex file in the dialog (3. Choose Files)

e. hit the 1.Reset to Boot Loader

f. then hit 4.Flash Firmware

that worked for me in the end, use reload page and reset device if you get steps wrong and want to get rid of the spurious repeated error messages. I also felt the need to manually / physically pull the usb out to fully reset the witch a few times while figuring out the above…

ps @Befaco I think it worked in solving the original problem, a bit of glitching audible when I change patches but doesn’t regularly interfere with the whole audio system as before. I presume I’ll have to actually build or use patches specifically setup to use the digital in/outputs though :slight_smile: