You wanna try! It’s a $2 toggle switch and an afternoon.
So.. the crux of this job would be finding room in the case of the h9 FOR THIS
https://lovemyswitches.com/4pdt-on-off-on-switch-solder-lug-short-shaft/
(there is a long-shaft version too… but I would use the short shaft if you are putting it on the top)
It is not a big switch… so think it could work.. but again- I haven’t checked. From memory, I think it would fit right in between the two foot switches.
Or maybe oriented horizontally coming out of the side? through the black part? That might be more elegant.
Anyway…you would have to drill the case to pull it through.. but once that is done.. the rest is easy.
You just desolder the existing footswtiches.. wire the source to the toggle. the switches to the toggle, and then to the AUX jack. You could tap the AUX jack from the PCB board… leaving you the option of using an external AUX switch in addition to this mod without interference.
The entire mod is strictly hardware-based (other than assigning AUX switch functions).. and entirely outside of your Audio signalpath.. so there would be no interference with sound, and no need for Software Accomodation.
I hope you try it! Take pictures and show us how it works.
