A passive preamp based on the S&B; TX-102 transformer volume controls. These are the silver TX-102s, which I got from John Chapman at Bent Audio. The casework is by Josh Stippich of Electronluv, carved from solid billet aluminum. I wired it with solid silver in loose teflon sleeving, using WBT silver solder. The selector switch is a Seiden 45-series (45007), 23-position dual deck. Jacks are Cardas rhodium plated (SRCA). The knob rides in a ball-bearing race and turns effortlessly. It has a single input and dual outputs wired in parallel. Many thanks to John and Josh - 2 of the greatest guys in audio!