LZX Castle modding

Let’s make this a Castle Modding Thread!
(as the Cadet Modding thread already exists)

I’ll start:
Today I added a LDR to a Castle ADC gain potmeter, and it works extremely well!
pot pins 1 & 2

so next up is voltage control.
I’ll also try the Bias pot.


Really curious about the voltage control one, it’s really something missing in the ADC i think.
Would be great to have a pot to control the amplitude of the control voltage input too, as ranges of gain & bias are pretty low.

Just tested the Bias pot, this works too. although the range is smaller
but this can work as a coarse & fine setting.
The range of the pots is indeed small With the LDR’s , you can use the remaining ‘dead’ range to fade in from white or black. This works great!

and tested CV input with a hacky vactrol. WORKS!
cv input: LFO. the vactrol is not super fast. it can do some audiorate modulation though. horizontal scrolling bars were visible.
1v video signal: I need to change the led resistor to see if this works

I tested the Gain pot, with a yellow (clear) led & 1k resistor + LDR and some electrical tape.

a little picture :slight_smile:

and a simple schematic

you can probably also use pin 2 & 3 of the pot. then It works inverted(not tested)
experiment with led types and resistor values
I used a clear yellow led and 1k
the LDR has no polarity, the LED does
black tape probably works better. or use a heatshrink . or a real vactrol