Fosgate Signature Tube Phono Preamplifier

HARD TO FIND - RARE 
FOSGATE SIGNATURE PHONO PREAMPLIFIER 
NO ORIGINAL BOX - Ser#1228

Jim Fosgate, most famous for his work on surround sound (Dolby Pro-Logic II, etc.) and car audio (Rockford-Fosgate car stereo), 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.

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.

The Fosgate Signature is a warm, detailed, inviting phono pre-amplifier with great extension at both frequency extremes. It is an extraordinary imager, with depth and width comparable to units at much higher price points.

• The design is the result of more than 100 different hand built preamp circuits dating back to the 1970's.
• 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 (6X4) 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 times oversize). The power supply simply holds the voltage across the capacitors like a "trickle charger". Internal 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 upperhalf (above 1KHz) is accomplished with a passive network between stage one and two. The lower half (below 1kHz) is accomplished with an active network around stage two and three.

• Gain: 42dB MM, 60dB MC

  Loading: 100 Ohm, 300 Ohm, 500 Ohm, 1 kOhm, 47 kOhm, 100 kOhm

  Capacitance: 50pf

   

  Tube Compliment:

  2 6DJ8's V1 and V2

  2 12AX7 V3 and V4

  2 12AT7 V5 and V6

  1 6x4

   

  Dimensions: 13 3/16"W x 10 3/4"D x 5 5/8"H

  Weight: 10 lbs