Quote Originally Posted by lurcher View Post
Yep, but passive potentiometer don’t have "THD: 0.03 % @ 1.8V"
Hi Nick
LDR's indeed can be made to behave as a passive potentiometer when arranged
the same, ie both devices as a passive L Pad circuit.

Your comments have combined what has been used as the DC measurements via the anode and cathode
to achieve low THD, and you have correctly pointed out fundamental differences in design to switches
with mechanical wiping contacts.

LDR's are a four terminal device, on one side a anode and cathode,
with the form of a very small red wavelength LED having a forward voltage
with resistance ON of 1.8v and Resistance off approx 1.32v

On their other side a variable resistor, varied by more or less
light intensity. They are an opto coupler, possessing excellent
attributes for audio.
LDR internal.jpeg

Cheers / Chris