Finally finished this JJ12AU7 preamp - SRPP. Finish is blue hammer tone on a Hammond wood cheek chassis. The cct. is constructed on a turret brd. with metal film resistors and Russian PIO caps. Pot is Alps blue velvet with 4oz solid brass gold plated knob. External PS supplies 260V HT and DC filament current. Two selectable inputs. Sound is very fast and snappy with good bass.