I have been recording piano solos using the simple record function on the MODX

? Which simple record function? There are two.
You can Record to a USB stick using the “Play/Rec” > “Audio” Recorder feature.
You can Record to the internal “Play/Rec” > “MIDI” Song Sequencer feature.

The computer typical has only a headphone out (which is really a poor audio source for the A/D IN)… connecting it to your MODX via the A/D In is perhaps the worst representation of your computer’s audio.
A better source would be connecting the computer’s USB to the “To Host” port on your MODX
Using the USB connection gives you pristine 24-bit quality.

You may have a reason to be using the A/D In from the computer, but you didn’t provide us with enough information about what you are playing back or why you would resort to connecting a computer to the synth’s A/D Input. It is our job to let you know there is a better way… if one exists.

Let us know.

The on-board audio recorder records the A/D input. So that can be used with a USB flash drive installed.

When you press record, then choose audio - you should see a meter at the bottom. Start playing your external backing track. If you see the meters moving - you know it will be recorded.

Bad Mister. I have Band in a box track coming in and its just for practice so not to concerned about the quality. Jason that worked! I just need to o choose Audio.

Thainks guys!

You should always be worried about the quality… lol.