Tuesday, October 7, 2008

Tea Box valve preamp with Cardas caps

My fascination for timber and electronics has lead to me assembling a valve preamp in a timber presentation Twinnings Tea Box. I like the idea of timbre helping to control cct. resonance and adding it's own signature to the over all sound. I also wanted to continue trying various coupling and input caps and for this build selected the excellent Cardas Golden Ratio caps.I did find their multi strands of fine leads difficult to work with if they were too long. But I was very pleased with the final sound. The box is lined with a tar and heavy Al foil layer for additional resonance control and RFI shielding. Computer stand-offs with rubber grommets fitted to them, support the brds. to further reduce cct. resonance.

You can see the cct. brds. above and rear terminal panel ready for installing in the drilled tea box. The timber is easy to work with in this box because it is a reconstituted wood and resin compound. So when drilling huge holes it does not splinter as other woods I have used. The valves are standard 12AX7(s) and other caps used are polypropylene types. All silver wire was used throughout, silver solder, Apls blue velvet attenuator and 4oz solid brass knob. The PS is remote in a metal enclosure. The amp is a two stage affair and over all gain is about 6db. Glorious sound.

No comments: