Questions & Answers

Quantum 26x32 not connecting to MacBook Thunderbolt 3 using Apple Thunderbolt 2 Adapter

0 votes
asked Sep 19, 2020 in Thunderbolt - Quantum by charlieherrick (150 points)
I recently purchased a Quantum 26x32 interface. I'm using an adapter to connect it to the Thunderbolt 3 ports on my MacBook, but it's not showing up in my audio devices. It does however show up in the Thunderbolt Device Tree. The Thunderbolt icon on the interface itself flashes.

From what I've understood, it shouldn't be an issue to connect the interface to Thunderbolt 3 as long as I'm using a genuine Thunderbolt 2 cable (not a MiniDisplayport cable) and Apple's T2-to-T3 adapter. I purchased both from Apple, brand-new.

I've tried restarting, and changing to a different port on the computer. I would really REALLY prefer not to do a factory reset on the computer because I have a LOT of apps installed and it would probably take me a week to get it all set up again.

I am using a MacBook Pro (15", 2016) running Mojave 10.14.6.

3 Answers

0 votes
answered Oct 27, 2020 by connorguiberteau (26,970 points)
Best answer

0 votes
answered Sep 26, 2020 by jleaqpds (200 points)
I have the same problem on a 16" 2019 MPB running Catalina. The Quantum works just fine on my 2013 MBP with Thunderbolt 2, but when I try to use the Apple Thunderbolt 3 to 2 adapter to connect to the 2019 MBP it won't connect (i.e. red power button and blinking blue Thunderbolt LED).

I've opened a support ticket with Presonus, but unfortunately I suspect their advice is going to be for me to buy the StarTech TB 3 to 2 adapter that they recommend for PCs ( and that others have found to solve TB3 connection issues (
+1 vote
answered Oct 6, 2020 by jleaqpds (200 points)

Update from my previous post: PreSonus technical support were able to diagnose and resolve the issue for me!

If the Quantum shows up under Thunderbolt via System Report (click Apple logo in menu bar -> About this Mac ->. System report -> Thunderbolt) but not in System Preferences -> Sound -> Output, then the issue is due to the Quantum's drivers being blocked by OS X after installation.

Specifically, on OS X Catalina (10.15) installation of the Thunderbolt drivers with Universal Control succeeds without any popup notifications. It's only after rebooting after installation that you will see a message in System Preferences -> Security& Privacy -> General (see attached screenshot at bottom of tab). You will need to click the lock on the bottom left and enter password to allow the blocked drivers. Then plug in and turn on the Quantum and it connects and shows up in OS X's sound output options. 

Quantum drivers blocked in OS X Catalina