Attack and decay time extension

Pulling the "attack" knob will give you attack of 5 seconds and decay til 3 minutes.
Press the red button and play a song !

Pot to replace with push-pull one :
- "attack"

Red and black wires connecting original cap emplacement
on board B with the caps on the "attack" push-pull switch.
(on my Synthi A MKI I kept the original electrolytic blue
1F cap and used a 10F tantalum one, on the AKS the
original one is tantalum)
Disconnect tantalum capacitor C46 (1F) of board B (note polarity). Solder its negative leg to the "D" lug and put a 10F tantalum cap on the "F" lug, with the same polarity (negative leg). Join both positive legs with a cable and connect it to the positive point of C46 emplacement on the board (inward).
Connect a cable between the "E" lug and the negative point of C46 (outward).
Of course, twist the cables and use tantalum caps, electrolytics might not retrigger.

Same mod can be done for on and off times, by adding a 22F electrolytic cap to C48 (2F).

No hole
Push-pull pots
Matrix MKI/MKII layout
Voltage controlled shape and response
Hi/lo range switchable oscillators

Simple Random Voltage Generator and Sample & Hold

Documents, manuals, dopesheets, links

Filter 18/24 db
Filter slew/unslew
Oscillator synchronization
"Synthi 2" interface