Crumar Stringman MIDI kit retrofit Installation manual Rev D5.1
Welcome to the metric system zone. Here we work with precision things and all dimensions are metric. 1" = 25.4mm. And yes, you need schematic reading skills.
Installation:
To your good usability select the friendly place to mount the LED, MIDI connector, button and PCB.
Drill all holes that required and mount connector, LED and button before soldering wires.
Drill dimensions:
For PCB drill holes 3.5mm.
MIDI jack (DIN5) = 18mm.
LED holder = 6mm.
Push button = 12.5-13mm.
Be careful with drilling hole for button, it have so small range to get hole too big.
Board dimensions and distance between screws:
Dimensions 105x90mm. Height 14mm with inserted connectors.
Holes diameter 3.5mm. Distance between holes 94x78mm.
Do not allow the board to bend, it can break the board.
All ribbon cables are 90cm. long, enough for placing all connections and you can cut extra length.
Panic button is not included in the kit. In case of panic - enough turn off and turn on the synth. If you prefer to install it part number is E-Switch RP3502MABLK
This picture shown:
First (1) pin/wire on all connectors. First wire will be start from this side.
The next picture shows the pinout for CN1 ribbon cable and pin number of wires:
Same you can see on bottom side of PCB for more convenience.
You will need to connect wire 4 (GND) with LED and button. All other wires in this kit required only one point of soldering.
. (7) V+ and (8) GND should be soldered on the next points in power supply:
So, now time to soldering key contact wires: All next connectors should be soldered to each key contact.
Board pinout and MIDI note:
Solder wires to key contacts and common bus(+12V rail): Wires from pin 1 to 12 on CN2 and from 1 to 5 on CN3 should be soldered to walking bass key contacts or to P107 board. It will be NO(normal open) contacts. 
Wire 6 on CN3 need to solder to any GATE key contact spring. On Stringman schematic it marked as D wire point.
Strings: Find key contact spring for note C (Do) on the first octave (left hand side) and solder wires from the CN4. Starting from wire 1. When you finish it, your last wire will be 12 and note (B) on this octave. Repeat all this on every octave, CN5-CN7.
On octave 5 (CN8), also start from wire 1 - C (Do). Wire 13 (C) should be soldered to last key C. Wire 14 should be soldered to key contacts common bus.
One small important thing - use hot glue to fix inserted connectors to protect from disconnecting them during vibration when you ride on tour. Also fix wires strong. Do not leave them holding only on soldering joints.
Process for set MIDI channel: User operations
Stop all MIDI traffic.
To teach with which MIDI channel synth will work - push the black button (LEARN) LED will blink two times and stay ON to wait for MIDI messages at one of 16 channels. He will in OMNY mode.
Send any note on the MIDI channel which you want for this synth.
When the synth receives MIDI messages, LED will blink five times and turn OFF. It indicates that channel was received and saved. Then will ON with every NOTE ON messages on the selected channel.
Now the channel saved to memory and will never change before you push LEARN button again and starts settings process again.