Why no audio being played through MOTU 8pre USB even though the meters on Logic and iTunes are blazing.


Feb 22, 2021
Agoura Hills, CA
I recently got a new MOTU 8pre interface. It has been working in spite of having to reconfigure the Optical In and Out everytime I startup. I have no ADATS or anything optical between the 8pre and the USB port on the back of my iMac.
After getting the CueMix FX to function as a stand alone mic and guitar pre without running Logic suddenly no audio is audible through MOTU 8pre USB even though the meters on Logic and iTunes are blazing.
Has anybody been through this and have a solution. Thanks.


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Apr 19, 2006
Hi, and welcome!

I'm a bit confused by the description of your problem. As I read it, you can get signals into Logic through the 8pre, but trying to replay the mix through the 8pre produces no output. Maybe you can't get the input to work either, but that was not clear.

When you say "suddenly", did this problem happen in the middle of playing a mix, or was it that you did not get any output straight after having used the 8pre stand-alone?

My reading of the MOTU description of stand-alone operation is that the 8pre (both USB and FireWire models) automatically switch to stand-alone converter mode if they are not connected to a PC via their respective interface. That implies that they should switch back to computer I/O mode when a software connection is made. Note that this does not necessarily mean that simple plugging into a USB or FireWire port will cause the switch back, rather that the software in the computer has to recognise that the interface is connected before the switch will work.

So the question in your case is: does your Mac show the 8pre as an active audio USB device? The corollary test would be to see whether the 8pre is still acting in stand-alone mode, with ADAT inputs routed to DAC outputs and ADC inputs routed to ADAT outputs. You could check this by unplugging the USB cable and using a lightpipe to jumper the ADAT out round to the ADAT in. You should check that analogue input signals appear as expected on the corresponding analogue output, and then whether that is still the case when you re-plug the 8pre into the Mac USB port.