How is the UMC204 connected?
Via USB or the audio outs? Are the headphones connected to the UMC204 or the computer?

On many interfaces if you record only a MONO signal it is sent on one side or the other (Left or Right). Meaning if you have a Mic plugged into the interface on channel 1 you will hear it's output on the left side during recording (especially with headphones).
Could this be the cause? Or do you hear 'everything' (including existing tracks) only on one side?

After recording, does the resulting track play on both sides?
Have you tried the MONO button on the UMC204? It may center the channel for you while recording..

Last edited by rharv; 10/29/16 01:00 PM.

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