Thank you Jorge for your answer,
I'm sorry I,ve seen it only now :)
I love this bass too...I was impressed by it in the 90's
and finally I've found one.
I've resolved bass signal problem, an engineer changed a piece
in the preamp section rising the output.
Now I'm trying to lower the bass action...tell me it is possible
to adjust the single string high in the bridge or it moves as a unique block?
Thanks
Stefano