The big difference between the Vox 847 and Dunlop Cry Baby GCB-95 pedals is that the Dunlop includes a power jack and filter. The Vox still relies on a 9 volt battery. Now the Wah uses very little power, but as long as your cable is plugged in you are using up battery life. The answer is to add a 9 volt power jack and while we are at it pop in an on/off L.E.D indicator.
I was once asked why the L.E.D mod is so popular with wah users. I mean if the wah is on you are generally rocking it with your foot so I guess it’s a case of really really short, short term memory loss, man.
When I do the Power Jack and L.E.D mod on the Vox I also put in a reverse polarity protection diode just in case you try to blow up your pedal with the wrong adapter.