Radial Engineering JD-7 Owner's Manual page 8

For Re-Mix - Connect the guitar and amplifiers as usual. Take
direct output from balanced XLR male output to mixer and
recorder. Record the dry track.
Replay the dry track, sending the signal to the XLR female input
on the JD7. Select 'INPUT-2' by depr e ssing the 'Select' switch on
the front panel to turn on the XLR input. Adjust input level to
suit. Now, play back the tr ack through your amplifiers while
trying different settings. This way, you can monitor different
sounds before committing final tr ack to tape.
Recor d ed Guitar