The cct. is the original Silcon Chip two stage valve preamp employing 12AX7s. I replaced the Sovteks with Golden Dragons. The rec. tube is a very old 5Y3 which visually appeared in good condition. A 10H Hammond choke and Hammond power tranny supply plenty of power to the amp. Alps blue velvet attenuator and quality passive components lift the basic build to a higher level of performance. A 4oz solid brass knob gives this retro-thermionic two part preamp an old world "dad's gramophone" look.
The preamp was sold within a few weeks of completion to a couple who grew up with "dad's gramophone" which resembled a science experiment but conveyed the passion of the music. Not much has changed where passionate reproduction is concerned. And it may still look a little like a science experiment.