Finished the Plexi but no working well

Hi Lolo,
well, people here are trying to help very often and you can make this fun for them:
Provide as much information as possible:

• links to documents: https://www.musikding.de/docs/musikding…lexi_schalt.pdf
• Measurements of the voltages at the pins of the JFETS against GND.
• what did you check yourself and what have been the results?
• Your problems seem to be related to the wiring, so photos of these are needed in addition.

There was no reason for your problems visible in the information, you provided, at least for me. I did not check the colour codes :-).
I think, the problem is probably somewhere in the wire links, so it whould be good to measure the resistance of these links and of the GND connections as well.

(I have now written a longer text, which needs time, than you did.)

Best regards Christof

Hi, I think the Problem is,that you reversed Tip and Ring at the Input Connector,check this out:

Best regards,
Micha