Siel MONO MIDI kit retrofit installation manual Vitalka Custom A03.1
This retrofit only for key triggering through MIDI. Octave transposing through MIDI is not allowed on this version of board. Note ON, OFF only.
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, MIDI connector, button and PCB.
Drill all holes that required and mount connector, LED and button before soldering wires of coarse.
Drill dimensions:
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 102x50mm. Height 14mm with inserted connectors.
Holes diameter 3.5mm.
Mounting outline and hole drills draft for board example sticker paper included.
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.
J1, J2, J3, J4 jumpers that divide common rails for every octave separate or split.
For SIEL MONO they should be open 
Bottom side jumper J5 should be open for SIEL MONO (For boards A03.1 and futurer)
The next picture shows the pinout for X6 connector ribbon cable and pin number of wires:
Same you can see on bottom side of PCB for more convenience.
(7) V+ should be soldered to any +12V point, (8) GND to any ground. Better if at a power supply near Ca4.
So, now time to soldering key contact wires: All next connectors should be soldered to each key contact
On the connector X4 you should skip all wires except 1 and 13.
At this point your brain can blow. Let me explain:
Find key contact spring for note (C) 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 (B) on this octave. Then solder Wire 13 to common key contact rail on this octave. - first octave will done. Repeat it for others octave.
On octave 4 PURPLE It only one key, last C (Do), you should start from wire 1. Wire 13 also should be soldered to last key contact rail. Skip else wires that marked on table "skip".
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.