Octal Custom

About the Octal Custom

The David Berning Co. Octal Preamp is a custom handmade pure vacuum tube preamplifier that uses four 6SN7 octal vacuum tubes in its line stage section, including Sylvania 6SN7 VT-231 NOS chrome tops. It features a capacitance coupled design with point-to-point internal wiring and a custom black aluminum chassis with a vented black aluminum power supply enclosure. The preamp includes a passive RIAA phono stage section using four 12SF5 octal vacuum tubes, with the option to convert to 12AX7 or 12AV6 tubes for lower noise. It uses an outboard choke type resonant switching pure vacuum tube power supply with 33JV6 vacuum tubes and has a cathode follower output stage with no additional filters. The preamp offers high level gain of 18dB, MM phono stage gain of 46dB, and MC phono stage gain with step-up transformer of 64dB. It includes Jensen JT-347-AXT step-up transformers (1:12 ratio), Cardas pure copper ground post, Furutech gold plated IEC inlet, GoldPoint stepped volume attenuator and selector switch, and Cardas gold plated female RCA input/output jacks. The unit weighs 60 lbs each and measures 23 1/4" L x 13 3/4" W x 15" H. Power requirements are AC 120V/60Hz with optional 220V/50Hz configuration. This preamplifier is designed for audiophiles seeking a pure tube sound with high-quality components and meticulous hand assembly.