Hey all, I was just looking at Mark Verbos' Arp Ring mod here: http://www.simple-answer.com/DIY.html http://www.simple-answer.com/ARPring.gif And I saw it has a 2n5172 and I was curious if that was replacable with another basic NPN like 2n3904. What's the difference between all those "general purpose" things anyway? Thanks, Rafael