master volume with a extra tube

[civic2006]

hi to all
is it posible to add a extra tube with a control pot before the pi
to use as mastervolume

 

[Arnulf]

Of course.

 

[mario13]

Hello,
You dont need to ad another tube. You can use apost phase inverter master volume. This is widely used in guitar amps. It basically consists of a double pot that blends the two 180 degree signals cancelling them out gradually.
Mario.