Convert a PAS3 to a PAS3x with tone controls that are out of the circuit when centered

[Thx1326]

Does anyone know of a mod, what parts would be needed or how you could convert a PAS3 to a PAS3x with tone controls that are out of the circcuit when centered? Or... possibly the instructions/schematic for adding a switch that would simply bypass the tone controls when not needed?

Thanks in advance.

 

[AllenB]

New thread created. Duplicates removed.

 

[rayma]

Does anyone know of a mod, what parts would be needed or how you could convert a PAS3 to a PAS3x with tone controls that are out of the circuit when centered? Or... possibly the instructions/schematic for adding a switch that would simply bypass the tone controls when not needed?

The PAS-3X used special mono pots that either had an open circuit in the middle (treble), or else had two wipers (bass).
However, the entire PAS-3 tone circuit can easily be permanently removed.

 

[petertub]

See http://www.audioregenesis.com/ for a well respected author.

Also, another difference is that PAS3X has a cap in series with the output which isolates a small DC from the output signal.

 

[rayma]

Yes, you need that unless your power amp input is AC coupled.
It's a 1uF 50V electrolytic capacitor.