Looking at rotary encoders for the frontpanel and THEY ARE EXPENSIVE.
5€ each, because i’m using a PC keyboard controller to detect panel input, I need the kind that gives pulses on one set of pins when turning CCW and pulses on another set of pins when turning CW.
The alternative is to use potentiometers, a couple of analog multiplexers and an A/D converter. That will definitly be cheaper but a pain to debug.
The rest is relatively cheap, 2 pots for pitchbend and modulation wheels and an XY-joystick for 2 assignable midi-cc inputs.
The pushbuttons cost allmost nothing.
I most definitly need to decide what parameters I wan’t to control from the panel of the keyboard because adding like 50 rotary encoders to the front will set me back for about 250€ and that is a whole lot more than the hardware in this synth costs.
As i’m using a 20 x 4 LCD panel for feedback I can choose to put some of the less frequently used parameters in the display for selection and use just one rotary encoder to change that parameter.