Valvetronix wiring / nerd level

[cronnin]

OK, I am trying to mod Vox Valvetronix AD30VT with a switch, to make both internal speaker and line-out working simultaneously.
Has anyone done this before?

I am not an expert so I need some guiding.
It seems I have to make a shortcut from point P1 to P3 through a switch.

What bothers me is P2. It is supposed to be grounded, and then, when you plug the phones it sends 'phone_dt' signal to the mainboards CPU while simultaneously muting the speaker.

I suppose that while 'phone_dt' is ON, then CPU sends more current to a 'line-out' directly from MAIN PCB (which is needed to drive the headphone speakers) ?

Could this current overload the 'drivers circuit' ?

 

[lastwinj]

Re: Valvetronix wiring / nerd level

try to lift the 3.3v control voltage for the gate of that switching jfet (thats my guess as to what i going on there) on the speaker mute. you can cut the trace, and if that doesnt work, just jumper a solid core wire to put it right.

shoulndt be an issue by the way. the CPU doesnt have any drive current most likely. it would be provided by a peripheral device/transistor or fet.

 

[cronnin]

Re: Valvetronix wiring / nerd level

Hm. Its all getting too complicated, I don;t want to bother you people anymore with this.