ARTEC EXP very noisy, please help

[Finnigan's wake]

After some experimentation, i decided to try this stuff in my battle bass (Fenix SH with schaller bassbucker), after removed both tone and volume pots (i use a volume pedal) and adding a series-split-parallel switch and a killswitch as well).
The bass in passive mode is totally quit without hum or other noises, but with the EXP activated there a LOT of noise, even if the kill switch is in OFF position... more: with the bass "turned off" i can hear the radio in my amp!!!

Some tip?

 

[Finnigan's wake]

edit: the kill switch is placed BEFORE THE CIRCUIT

 

[Crater]

The killswitch should not allow an "open" circuit to occur, that will cause noise, the same as plugging a cable into your amp with no bass on the other end. The killswitch should connect the signal "hot" wire to GROUND (earth).