This build centres around the 12AX7 tube and a SRPP schematic I have used a number of times. The custom part is a remote control which I have never used before. The motorised Alps Blue Velvet pot comes as a single unit with motor and control circuitry smartly attached on the rear. The remote is small with only volume usable. It works well but the steps are a little large and the preamp has a lot of gain.
To fix both issues I have some Tung-Sol 12AU7s coming which have a much lower gain and will allow the remote pot to be better controlled. If you pair this preamp with a power amp of low gain the X7s are a better selection. I’m very pleased with the finish which is Gun Metal epoxy hammertone. The chassis has wood cheeks and the whole appearance is understated and vintage industrial looking.
Two inputs selected from the front switch, silver plated fine copper wire for hookup and 1uf of PIO output caps makes for a good sounding preamp. The PS is external and has a Hammond 5H choke in a double Pi configuration. Also there is 300uf of snubbed high voltage caps for filtration. A 4uf PIO snubbed cap is the final cap and situated in the preamp. This always improves overall sound. Filament voltage is DC and the preamp is dead quiet, fast and detailed sounding.
