Saturday, June 25, 2011

Single Stage Tube Preamp MKII

Shown here is the second build of the simple but good sounding preamp. In this version (MKII) two values were changed in the cuircuit which has caused a sharp drop in distortion (0.2%) and better performance from the whole preamp. Internally the build is neater and tighter. With even shorter signal path than in the previous build. The finish is beaten copper.

Again single brd. construction prevailed with no PCB. All component-2-component wiring using silver solder and wire wrap wire to connect to the pot and RCAs. An Alps Blue Velvet pot is used on the output with a solid brass black chrome knob. Any 12AU7 can be rolled to the provide different timbres and tone. The cast Al case is damped with tar/Al heavy foil and thick silicon feet fit-off this fine preamp.