Tuesday, May 18, 2010
Remote driver stage for Bread Board amplifier
Because the Bread Board amplifier (Be Bamp) performed so well, though at low volumes, a driver stage was built for it. This stage is remote from the rest of the amplifier and is joined to the amp by interconnects. A multi-pin, high grade, plug and socket connect the 400V HT+ and the 6.3V filament voltage to the driver stage. This single stage front-end has been constructed in a Twinings Tea Box to match the two stage valve preamp else where on this bLog. Having the driver stage remote allows the trial of different driver stages while sharing the power stage and the and a common power supply.
The same drive stage as in the Merlot amp was used. This employs a 6N1P Russian tube. Parts of the original schematic were upgraded and Russian military paper, foil and oil caps were used for inter-stage connection. There is no volume pot or input capacitor. Low ESR grade caps were used where possible and pure silver wire used in the signal path. Construction is all component-2-component with no PCB or any other cct. brd. The timber Tea box is bitumanised Al foil lined.