Q: MOTU Ultralite Mk3 Hybrid Freezing & High Pitched Noises
Hi all -
I bought a MPB 2015 13" pro retina with 16gb RAM and a 2.9ghz i5 processor, El Capitan in December and have been trying to get it to work with my MOTU Ultralite Mk3.
I have installed the latest drivers and firmware from MOTU and have kept OS X up to date, but I keep running into strange problems when the CPU is under load. When I have a critical mass of VSTIII or AU plugins loaded in Mainstage / Presonus Studio One 2 (CPU around 40%), the interface suddenly freezes and emits a high pitched whine; the meters on the front start to pulsate at random. The host programs continue to work fine (if I switch to the internal sound output), but the only way to get the interface back up and running is to power cycle it and restart the program. I got it to do the same by simply switching the DAW between 32 and 64 bit processing; the CPU spiked briefly and the interface froze. The issues happen via USB and Firewire (via the Thunderbolt>Firewire adapter).
Initially thought it could be a problem with the MOTU unit, so I tried it with my old PC laptop in Studio One 2 (same version). The CPU (i5 2.6ghz) was running at 100% and the audio went choppy, but the unit stayed online and didn't freeze whatever I tried.
I'm aware of issues with El Capitan & FW audio, but it doesn't explain why it occurs with USB as well.
Any ideas how I can stop this from happening?
Thanks,
Matt
MacBook Pro with Retina display, OS X El Capitan (10.11.2)
Posted on Feb 15, 2016 2:59 PM