Power for the Drum Tone Board can be tapped from the midi2cv8 aux. power connections using the parts shown to the left. The nominal "+5" bias line of the Tone Board will be more like 7 or 8 Volts using the values shown and the Tone Board will like this fine (better than 5V, actually).
The added parts can be put on the 9302k Tone Board circuit board as shown here. Note that the added diode D1 "flies", i.e. while the banded end solders to the hole in the circuit board, the other end is soldered to the wire that goes to the midi2cv8 (9700) aux power "+" point. Insulate the junction of the wire and the diode with sleeving or tape.
Connections from the midi2cv8 outputs (O1 - O8) can be connected to the seven drum sounds on the Tone Board in any arbitrary order as summarized in the illustration. Notice the added 1N914 signal diode connecting Output 8 to R44/C25 on the Tone Board. This diode lets O8 (or any output you choose) gate the noise source "on" without also triggering the Tom sound that usually accompanies it for Snare. This allows custom mixes (more velocity on the Noise produces more snare rattle, more Tom velocity more strike tone). In general, more interesting sounds can be produced with mixes of the basic tones.