Feedback? That would be my first guess. But without knowing what you are feeding to the A/D inputs I can only guess. Please provide a bit more information.

Thanks for your reply. It doesn't matter what device or cables I run to the input, the problem persists. I tried guitar, mic, sampler, record player, cd player..switched out the cables..it sounds to me as if the synth is doubling the input signal and playing both slightly out of sync, giving a minor echo effect (yes i turned off all effects). I'm contacting customer support and hoping the problem is user error.

If you'd like help here, pick one item and tell us what you're doing (worries me when you say "record player" ??? What's that? 🙂

Let's take the CD PLAYER... (Record player scares me)...
Go to [UTILITY] > "Settings" > "Audio I/O"
Set the A/D INPUT = Line (green)
Connect the left and right audio outputs of the CD player to the left/right A/D input jacks of the Montage.

On the front panel activate the A/D Input On/Off button
Raise the Gain so that the peak light begins to flash on the loudest portions.

Now we assume you are monitoring your Montage either through headphones or a quality pair of monitors or sound reinforcement system. And we also assume you are not connected to a computer at this time. Correct? Let us know.

I re- updated the os and it is working now as intended. I still don't know what caused the problem but I am glad to have the inputs working, as they sound great. Thanks for your attention. 🙂