Monday, August 10, 2009

Twinings Tea Box preamp with remote valve PS

This was the first of the remote, valve rectified Twinings Tea Box preamps I made. I have just recently completed another, commissioned by a supporter of DIY gear in Denver. In this build I used the original Jupiter, beeswax and paper capacitors. Sadly these caps are no longer made and a more modern beeswax cap has replaced them. In this build, as in the latest, silver wire and silver solder is used throughout the audio path.

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.