Oh this one worked for me ... briliant idea ...
First I lowered channels volume but ... Few times I almost died dialing by mistake the mode knob which reverts to higher channel volumes ... bad bad bad !
Then I experimented with extra resistor connected between wiper of Master Volume Pot and Ground but it requires opening and making changes inside the amp ... I've made it on a cable but still ... why to do it? It also reduces the highest gain unnecessary ... also bad !
Juergen proposition is most elegant and working !
Now I have an extra box with second volume pot (100k log as suggested) connected to pre-out and amp-in (send/return) permanently so my channels volume is now around 70 so the popping (while preset switching at low chan vol) issue is solved by this !
Juergen - great thanks !
