I was looking at a freinds SB-220 and found that C21 (a .02 cap across the tube side of the filament choke) had been removed. Any reason why this should be taken out? Should I replace it? The amp appears to work fine without it. cheers, Paul - VA7NT ex VE7CQK - email: paule at sfu.ca "Those who hear not the music. . . think the dancers mad."