Yamaha EAD10 Owner's Manual page 47

 Switching to AUX IN Recording
The Input Source must be changed to record from the [AUX IN] jack.
1.
Press the [RECORDER] button.
2.
Press the button below "SOURCE" ([F3]).
When recording to the Main Unit
3.
Press the button below "YES" ([F1]).
The setting is changed to the AUX IN recording.
NOTE
Your performance does not sound and is not recorded while
in AUX IN recording.
After you finish recording, the EAD10 returns to the normal record settings.
When recording to a USB flash drive
A confirmation message appears.
Basic Guide
Recording Your Performance
EAD10 Owner's Manual 43