This is Abacus ACF-2 Aikido tube buffer preamplifier based on John Broskie’s Aikido Cathode Follower schematic as described on TubeCAD website
http://www.tubecad.com/2011/01/blog0198.htmACF-2 is unique in terms of its architecture featuring extremely low distortion together with very low output impedance and high input impedance.
Preamplifier has zero gain and serves as a tube buffer with constant input (high) - output (low) impedance which is perfect for use with modern sources and amplifiers. In my setup with a pair of NCore NC400 the volume dial rarely goes past 11 O'Clock.
Features:
3 inputs and 1 pair of outputs.
Remote controls all functions of the preamp - on/off, volume, and input selection.
Front panel LED’s display the input selection.
30 sec. start-up output mute to prevent pops and noise on the output during warm-up. There are no pops or noise when turning the preamp on or off with power amps on.
Front panel LED indicates "ready" state.
12V remote trigger output.
Volume is controlled by 128-step relay attenuator to achieve perfect balance and low noise.
Preamp is constructed with highest quality parts - Holco, Allen-Bradley, and precision Dale resistors, PIO coupling caps, Teflon silver signal wire.
Tubes used are Russian 6N1P which sound great, are inexpensive and plentiful. They could be substituted with 6dj8 or similar types.
I am currently using this preamp in front of my Hypex NCore 400 amplifiers and it performs great. I also tested it in front of TPA3116 and 300b amplifiers and its performance was excellent - no turn on / turn off noise, no hum or hiss, completely transparent musically.
Asking $690 shipped in CONUS
