Crumar DS2 Midi Upgrade Vitalka Custom
This retrofit only for key triggering through MIDI. Octave transposing through MIDI is not allowed on this version of board.
Welcome to the metric system zone. Here we work with precision things and all dimensions are metric. 1" = 25.4mm.
Installation:
To your good usability select the friendly place to mount the LED, DIN5 MIDI connector, button and PCB. Mount connector, LED and button before soldering wires.
Important:
For organ key contacts you need to be isolate ground bus. It can do extra cacophony-humming noise on output, but if not do it - MIDI for organ section won't be working.
Use packing tape or something like this for that. You can also remove this bus, but you will need to solder jumper wire for connect ground wire from other side to restore connection. See pictures below
Drill dimensions:
DIN5 = 18mm.
LED indicator = 6mm.
Push button = 12.5-13mm.
Be careful with drilling hole for button, it have small range to get hole too big.
Board dimensions and distance between screws:
Board dimensions 106x90mm
Holes distance 94x78mm - Use it for drill holes for board mounting.
Holes diameter 3.5mm
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.
This picture shown first (1) pin/wire on all connectors:
Onboard jumper configuration: LJ1, LJ2, LJ3, LJ5, LJ6, LJ7 closed.
The next picture shows the pinout for 8 wire 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+ should be soldered to any +12V point, (8) GND to any ground.
In cases if voltage drops, connect V+ wire before current sense resistor or to pin 13 of LM326
Board pinout and MIDI note:
Here you can see two identical key contacts group connectors for two groups of contact springs. At this point your brain can blow. Let me explain:
Solder first one group of contacts, then go to the second group. Find key contacts for note E on the first octave and solder wires from the YELLOW connector. Starting from wire 1. When you finish it, your last wire will be 12 and note F on this octave (First key). Your move will go from right to left. On octave 4 PURPLE, you should start from wire 5.
Wires marked "skip" should be skipped except wire 14 which should be soldered to key contacts common bus, every for every bus. For second group - repeat the same.
Wire colors to key contact may vary, and can be not in the same sequence on ribbon cables. But always first wire is first to you if board placed as to this picture below
Here is some explanation:
Shield is ground wire that soldered to ground bus. And second group 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:
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 on OMNY channel.
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. And 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
This manual can be not so much clearly to understand, and may be edited for fix it.
Last change: December 2. 2025. Added photos and pinout correction for board Rev 5.1