UR44C MacBook Pro USB-C port issue audio drop out

are all 4 thunderbolts 3 USB-C ports of a MacBook Pro fully compatible with the UR44C?

I connected directly to the unit, no hub used here, I am using a Cable USB C to USB C 3.2 Gen2*2 Thunderbolt 3/20Gbps PD 100W.

Depending on which port and if other devices are connected there from time to time audio breaks, the audio is not output, it stop then start again, a bit like mute/unmute for about 1 second the audio is dropping out.

Specifications from Apple for the MacBook Pro (15-inch, 2019)

Charging and Expansion

Four Thunderbolt 3 (USB-C) ports with support for:

  • Charging
  • DisplayPort
  • Thunderbolt (up to 40Gb/s)
  • USB 3.1 Gen 2 (up to 10Gb/s)

What could be the cause?
Is there a solution?


Are you running the UR44C off the USB (bus) power or external power supply? If bus powered, are you using USB-C (both ends), 3rd-party cable? (Not sure whether your MBP is only that kind. Cable quality is important, esp. if using USB-C.) Does it work differently if the MBP is on battery or plugged in? Etc.

Just speculating, flapping gums here… I only tested mine with the iMac for running off of bus power, and it seemed to work Ok, but I could imagine that if you’re running on battery power on the MBP, there’s going to be some limitations providing bus power at a level the 44C could require, especially if you’re using bus powered devices on other ports, too.

Hi @kloder , thanks for the questions,

I am running the unit bus powered, it’s not an official apple cable but a 3rd party. The MBP is always connected to power source via official cable and power brick.

Have you made the latest UR-C updates? Firmware ? dspmix FX? driver?

my specs
macOS Catalina Version 10.15.7 (19H2)
Intel mac based

Boot v1.00
Main v1.50
driver v2.0.5
DSPMixFX version 1.5.1

it happens when playing music (outside DAW) for instance on Youtube or Apple Music App


Is the Apple Music App problem just when streaming or does it also happen with local music files? YouTube is obviously streaming, so there might just be some resource contention or WiFi hiccup, I suppose.

Are you using the “superspeed” mode of the driver?