Adcom GFA-5500 Factory Renewed 200 Watts x 2 Stereo Amplifier

Provided by OneCall

Note: Many of the design features in the GFA-5500 are virtually identical to the GFA-5800 power amplifier. The primary difference between these amplifiers is power output. The circuit topology and design concepts are virtually identical.

POWER SUPPLY
Completely Separate Secondary Main Power Systems.
The GFA-5500 has a specially wound high power toroidal transformer which completely isolates the two channel secondary systems, not even sharing the ground connection. This eliminates ground loops and greatly reduces the possible interactions between power channels.

High Capacitance Storage
Each channel has nearly 120 Joules of energy storage, adequate for 14 kilowatts of power at 10% ripple. Under normal operation, the power supply ripple voltage is less than 1%.

Separate High Voltage Front End Supplies
The front end circuitry of each channel is supplied power by its own high voltage system - including separate transformer windings, bridge rectifiers and filter capacitors for each channel. This eliminates interaction between the early gain stages of the amplifier and the high power occurring in the output stages. The front end system is operated at a higher voltage than the output stage. This not only improves the distortion characteristic of the front end, but allows the front end to drive the output stage to its supply rails - obtaining every bit of available power to the load.

In Rush Limiting
The power supplies feature inrush limiting, which prevents the high current surges, which would normally accompany the charge cycle of the transformer and the power supply capacitors on turn-on.