World class audio engineer Jim Fosgate is the vision and expertise behind the Fosgate Signature Tube Headphone Amplifier. The Fosgate
Signature embodies unique and patented circuit topologies, elevating the headphone listening experience. The genesis of the
design started over 2 decades ago. Countless man hours of working with every possible major circuit approach was not just explored,
but designed, built, and auditioned by Jim Fosgate himself.
The circuit incorporates 12AX7 vacuum tube amplification in the low
distortion SRPP configuration, similar to our Signature Phono Preamplifier, winner of the 2011 Golden Ear Award from The
Absolute Sound magazine. High speed, high current video buffers are used to drive headphones directly. This provides a pure audio path
with low output impedance, low distortion, and wide signal bandwidth.
The bass boost equalizer circuit is designed to give the headphone 4 listener defined low frequency bass impact without bass boom. This
circuit has been used in different forms in many products including Rockford Fosgate Car amplifiers. Jim Fosgate received US patent
number 3,883,832 for this circuit in 1975. It is called a “SINGLE ELEMENT CONTROLLED TWIN T FILTER” and has a much steeper
curve than a bass or loudness control. It changes frequency and amplitude (Boost) with a single control. When the control is set in the “Min”
position, the boost is applied at a lower frequency than when the control is set to the “Max” position.