LED in two stage effect

[red_92]

ok guys,i have a two stage guitar effect -two valvecasters in series;the first one will be always on and the second one will be controlled by a dpdt switch with true bypass
now...i want a led to lit when the second valvecaster turns on-the led will be powered from the same power source (12v wall wart) which powers the valvecasters...where should i put that led?

[ACS]

You need a 3pdt, and switch it off the third pole. Or, use the 2pdt that you've got with a millennium bypass...