Siel Cruise (Dual A03.1 Boards) MIDI kit
This is upgraded version with two boards that can set independent MIDI channel for each part of synth.
Please read instructions twice before start doing anything.
Installation:
To your good usability experience select the friendly place to mount the LED indicator, MIDI connector, button. Place Board_2 under Board_1. Like on this picture.
The "MIDI" jack and pushbutton can fit near jacks at rear panel. Activity indicator can be placed on top panel. Drill all holes that required and mount connector, Indicator and button of course before soldering wires.
Drill dimensions:
MIDI jack (DIN5) = 18mm.
LED holder = 6mm.
Push button = 12.5-13mm.
Be careful with drilling hole for push button, it have so small range to get hole too big. See below dimension ranges from their datasheet. Drill a bit less and file it to fide fitting.
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 for both boards.
Do not allow the board to bend, it can break the board.
After mounting boards, connect boards together with 10pin cross board cable and 8pin cable.
Ribbon cables are 90cm. long, enough for placing all connections and you can cut extra length. Except 8pin and 10pin cable.
The next picture shows the pinout for 14 and 8 wire ribbon cables. And also pin number of wires: Same orientation when board facing to you.
More visual wiring:
(7) V+ and (8) GND should be soldered on the next points:
This picture shown first (1) pin/wire on all connectors:
Board_1 is for MONO. Board_2 for POLY part of synth.
You can see closer to you board with key contacts for MONO section, on back for POLY.
Board_1 pinout and MIDI note for MONO section:
Solder wires to key contacts and common bus for every octave. On the last octave only two wires used for this model - High C and common wire, skip which marked skip.
Board_2 pinout and MIDI note for POLY section:
Solder wires for each POLY key contacts springs pad and common buses for left and right part of key bed.
So, looks like installation finished. Now time to explain how set MIDI channel. This is what you need to know for starting use this retrofit.
Process for set MIDI channel: User operations
Stop all MIDI traffic.
To teach with which MIDI channel synth will work. MONO section: push and hold the LEARN button for a 1-2sec. LED will blink fast four times and stay ON to wait for MIDI messages at one of 16 channels.
Send any note on the MIDI channel which you want for this synth.
When the synth receives MIDI messages, LED will blink fast four times and turn OFF. It indicates that channel was received and saved. Then will ON with every NOTE ON messages on the selected channel.
For set MIDI channel to POLY section : push and hold the LEARN button for a 2-4sec. LED will blink slow four times and stay ON to wait for MIDI messages. Of course you can set both channels is same.
Now the channels saved to memory and will never change before you initiate the settings process again.
In case of PANIC, or you want to exit from settings - Short push the LEARN button.
PANIC - Short push
MONO - Push for 1-2sec. LED blink fast.
POLY - Push for 2-4 sec. LED blink slow.
_____
At moment when synth power on, all keys will be sound less a half second. If on this moment MIDI commands will received on saved channel it can be cause of panic.
Last update: March 23. 2026.
