FOSGATE SIGNATURE PHONO STAGE
Musical Surroundings is pleased to introduce the Fosgate Signature phono preamp from world-renowned audio designer Jim Fosgate.
Most famous for his work on surround sound (Dolby Pro-Logic II, etc.) and car audio (Rockford-Fosgate car stereo), Jim listens to tubes and vinyl in his personal system. His passion for analog and tube sound has lead to the development of the Fosgate Signature phono preamp. Jim Fosgate has chosen Musical Surroundings to bring his very special design to market.
Over the past 30 years, Jim Fosgate built and tested more than 100 different designs before settling on the one that became the Fosgate Signature. This design features all tube amplification and rectification with no solid-state devices in the signal path, switchable moving magnet/moving coil gain setting and variable loading settings from 100 to 100K ohms. The industrial design of the Fosgate Signature is clean and modern, using blue LED illumination for the tubes, yet also retro, proudly displaying its 7 tubes (with no cage) and real wood end caps.
2 6DJ8's - V1 and V2
2 12AX7 - V3 and V4
2 12AT7 - V5 and V6
1 6X4 - high voltage rectifier
The design is the result of more then 100 different hand built preamp
circuits dating back to the 1970s.
. All amplification is accomplished with the SRPP (push pull) configuration
for the best possible linearity, lowest noise and distortion.
. No solid-state devices are placed in the signal path and a tube is used for
the high voltage rectifier.
. The power supply is very different and contributes to the high
performance. There are no regulated power supplies. Each tube stage is
powered by a separate storage capacitor that acts like a battery. These
storage capacitors are very large (10 to 20 time's oversize). The power
supply simply holds the voltage across the capacitors like a "trickle
charger". PC board layout is "Dual Mono". The channels are located on
opposite sides of the circuit board in near mirror image with dual triodes in
a row down the center.
. The first stage has no NFB to interact with the cartridge. The second and
third stages are enclosed in a single feedback loop incorporating both
positive and negative feedback.
. The RIAA network is divided into two sections, one passive and one
active. The upper half (above 1KZ) is accomplished with a passive
network between stage one and two. The lower half (below 1KZ) is
accomplished with an active network around stage two and three.