Quantum HD8 sync to RME Fireface

[Dr.Jackle]

MacBook Pro 14"
Sequoia 15.7.3
Logic Pro X

I'm trying to use the Presonus Quantum HD8 as and ADAT preamp with RME Fireface UFX III. Quantum Clock Source is set to ADAT and Standalone Mode is set to ADAT. I have an optical cable connected from Quantum ADAT 1 Out to Fireface ADAT 1 In. The sync LED on Fireface keeps flashing, which means that Quantum is locked but not synced to Fireface clock.

When I change clock source from Logic to 44100 Hz, the clock in the Fireface changes, but in Quantum settings the clock source is shown 48000 Hz. I'm unable to change the clock frequancy in the Quantum menu, nothing happens when I select Clock Source and scroll the wheel, trying to change the clock frequency to manually match Fireface & Logic.

Despite, I feed a signal to Quantum channels 1 and 2, and get the same signal to Fireface ADAT inputs 1-2. When I connect the Quantum to MacBook Pro with a USB cable, I lose signal in TotalMix ADAT inputs 1-2.

Does anybody have advice on how to fix this?

 

[LUpton]

You have an air gap… You have to have an optical cable connected from the RME Adam OUT to the Quantum adat IN for the clock signal to get to the Quantum, with the output cable from the Quantum attached like you have it. I do this all the time with an old RME 9632 and a different adat to analog interface and it always works perfectly.

 

[Dr.Jackle]

I just connected an ADAT cable from Quantum ADAT 1 Out to Fireface ADAT 1 In. Unfortunately it didn't have any effect on the issue.

 

[Dr.Jackle]

Update: Switching the Quantum on/off and switching the clock source temporarily to another option and back to adat solved the sync! I feel quite stupid, I've only synced stuff with word clock before and assumed it's a two way street with any digital protocol. Alas, I was wrong!

The ADAT signal still dissapears in TotalMix if I connect a USB cable between Quantum and Mac. Is this how it's supposed to be?

 

[LUpton]

If you have 2 separate adat cables connected, one as rme to quantum, the other as quantum to rme, and clock switches on the quantum set to adat , this will make the quantum become an adat extension of the rme. Don’t try to use the quantum with usb at the same time you are using the Fire face. It probably won’t work, as you have seen.

 

[Dr.Jackle]

If you have 2 separate adat cables connected, one as rme to quantum, the other as quantum to rme, and clock switches on the quantum set to adat , this will make the quantum become an adat extension of the rme. Don’t try to use the quantum with usb at the same time you are using the Fire face. It probably won’t work, as you have seen.

Sure, using two audio interfaces at the same time is a bad idea, even if they might work as aggregate devices. I was mainly interested in remote control of the Quantum gain, phantom, loading scenes etc. But it seems configuring and loading the scene is better done in advance, and after then it's just manual control for the Quantum.