Gaussmarkov Spring reverb. Power supply?

[Lurch]

Hi!

I'm new when it comes to creating stompboxes and circuits, but still I wanted to make a spring reverb. So I have got all parts needed to create Gaussmarkovs version of the Forrest Cook spring reverb and have etched the PCB (as listed in Gaussmarkovs part list). I'm planning to have the circuit powered by a AC/DC converter as it needs 12Volts according to the schematics. So my question is, how do I know what current the curcuit needs or can handle? Is it depending on the transistors collector current? I guess my question is something that is basic knowledge though, so excuse my non-knowledge  

http://gaussmarkov.net/wordpress/circuits/spring-reverb/

kindly regards,
Lurch