ARP Quadra MIDI kit retrofit Vitalka Custom installation manual

Installation:

Select the right place to mount the LED, DIN5 MIDI connector and button on your synth (on the back panel near jacks for example).
Drill holes and mount DIN5 and button before soldering wires. 
 

Drill dimensions:
DIN5 18mm ( "imperial" 11/16" or 3/4" )
LED = 4.8-5mm.(better if less 5mm to strong holding in the hole) ( "imperial" 3/16" )
Push button = 12.5-13mm ( "imperial" 1/2" )

Board dimensions and distance between screws:
Board dimensions  102x50mm
Holes distance  94x39mm
Holes diameter  3.5mm 

Do not allow the board to bend, it can break the board. Connect IDC connectors and mount the board, or hold board when inserting connectors. 

All ribbon cables are 1M 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.

The next picture shows the pinout for 8 wire ribbon cable and pin number of wires:
1 - DIN5 4pin
2 - DIN5 5pin
3 - LEARN
4 - GROUND
5 - LED ANODE
6 - RESET
7 - V+ 
8 - GROUND

(7) V+ and (8) GND should be soldered on the next points:

All next wire should be connected to each key contact or to the main board:

Board pinout and MIDI note: ZOOM

All note wires should be connected to every note key contact and common buses
Common ground key contacts bus on synth should be isolated from key contacts or removed. This bus was for prevent open input for logic buffer. After installing this midi retrofit she is no needed anymore. If not do this - MIDI control wont be work. Now logic gates is always connected and will not interferents random levels.
ARP Quadra key contacts: ZOOM

 

 Now you can remove the physical keyboard from your synth if you want.

One small important thing - use hot glue for fix inserted connectors for protect from disconnection them during vibration when you ride on tour.  Also, fix wires strong. Do not leave them holding only on soldering joints.