“SOLD”
For sale is my Vacuum Tube Audio SP14 preamp that I build 3 years ago. This is a great preamp and is the same circuit used in the Don Sachs preamp.
The power supply of the SP14 is a fully dual-mono design. Each channel has its own B+ and its own filament supply. This gives better separation between channels and lessens the load and interdependence. The B+ power supplies are tube rectified which gives a soft-start and simplifies the design compared to a solid-state design, and it also sounds better! Then the B+ is fed to a voltage regulator for each channel that eliminates all variation in the supply, and reduces the noise by at least 20db, making for a deep, totally dark background. It also uses Audyn Cap Q4 MKP Metalized Polypropylene Foil capacitors in the B+ power supply. The two filament supplies (one for each channel) use ultra-fast Schottky diodes, and then the filament voltage is regulated by a low-noise, low-impedance device that is completely isolated from the audio signals.
There 5 inputs and two different outputs. Output 1 uses 0.22uF K40Y PIO capacitors and output 2 uses 1.0uF Audyn True Copper Caps. Ouput 2 is good with solid sates and tubes amps. I have used it for both types and it has always sounded great.
The chassis was custom made and is from Landfall Systems. It is 1/8” thick clear anodized aluminum.
The preamp includes four blackplate Sylvania 6SN7GTBs matched by Brent Jessee, four Russian 6H8C (6SN7GT), one National Union JAN CRC 6X5GT, two RCA JAN CRC 6X5GT blackplate.
The unbuilt kit with all the upgrades would be over $1600. Getting a built version would cost an additional $430.
Price is $1200 including PP and shipping in the USA.
