Adding a treble control to a Carlsboro 60 pa thoughts

[Yosser]

This is just an idea, is it possible to add a treble control or treble boost to this amplifier, it has a presence control (which maybe a treble control in disguise) but no treble control named as such, could this be an easy mod or would there be performance trade offs?
The stack seems to be like a James stack or based on baxandall - any thoughts?

[sluckey]

The Presence pot ***IS*** a treble pot. Nothing to do.

BTW, I just noticed your very dangerous bias circuit. The bias pot allows the bias voltage on pins 5 of the EL34s to be adjusted to zero volts! Doing so will quickly kill the EL34s.

[Yosser]

The Presence pot ***IS*** a treble pot. Nothing to do.

BTW, I just noticed your very dangerous bias circuit. The bias pot allows the bias voltage on pins 5 of the EL34s to be adjusted to zero volts! Doing so will quickly kill the EL34s.

Ah, I thought as much in this case
I have modified the bias circuit be a marshall design to prevent that from happening.