This is the bare PCB of an audiophile grade pre-amplifier, based on a legendary conponent, SONY's V-FET 2SK79. The pre-amplifier is wired in SRPP configuration, based on the design by Mr. Yasui Akira of Japan.
Background : Yasui Akira was a prolific contributor to Japan audio magazine MJ the last 50 years. He sadly left us in February 2020. In memory of this audio guru, a great promoter of DIY audio designs for half a century, we actualized this design with our layout effort. The design adhered closely to what Yasui had published in MJ. We have included a volume control on board to make the preamplifier a more integrated design.
2SK79 is an unique small signal V-FET ( or SIT) manufactured by SONY in the mid 70's of last century. V-FET is renowned for their triode-like characteristics. By chance we obtained a limited stock and matched the devices to offer a limited quantity of matched set for this board.
1. SRPP PCB one piece ;
2. Idss matched 2SK79 two pairs.
The assembled board is for reference only.
There is a wide spread of parameters in 2SK79 manufacturing, and we are only able to match a quad set from each 50 individual pieces. The supply is thus very limited and it can end at any time.
Supply voltage : 30VAC- 36Vx1 AC 200mA
PCB dimension : 182mm x 122mm.
Frequency response : 40Hz - 300KHZ +/-0.5dB ( 4.7K loading, 1uF output coupling cap.) ; 20Hz - 300KHz +/-0.5dB( 4.7K loading, 10uF output coupling cap.)
PCB thickness : 1.6mm, 2 oz ( 75um thickness !!) copper deposition. Gold flushed surface.