Boss Dr. Rhythm DR-3 Owner's Manual page 97

Chapter 11 Connecting and Using External MIDI Devices
Recording Sequencer and Rhythm
Machine Performances
When connecting a sequencer or rhythm machine
and recording the performance data from it, the
start of recording with the DR-3 is controlled
from the connected device.
fig.10-08
MIDI OUT MIDI IN
MIDI Sequencer DR-3
etc.
Press [MANU] on the DR-3 so that the button
lights up, then press STEP REC [ ]. The DR-3
begins recording at the same time the
performance from the connected sequencer or
rhythm machine is played back.
To stop recording, press STOP [ ].
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