Hi Florian.

It is a sine wave that I am using from the A-145.
I have also tried the square and triangle outputs from my A-143-4 - it still behaves the same way, but with different waves the ''click'' becomes more or less pronounced in character - but, not volume.

With resonance turned up you get the expected ''sweep'' sound but with the click at the end of the modulation cycle.

Kind regards