Fostex 600 - DESCRIPTION

DESCRIPTION
A truly integrated power amplifier the FOSTEX Models 600/300 incorporate 3-step Darlington
circutry that is push-pull in all stages, designed with minimal surfaces it obsoletes every other
power amplifier available. And, beneath its smart case there's a big damping factor, expansive
power bandwidth, and some of the most fascinating technology yet developed.
This highly sophisticated, full capacity power amplifier made to the most exacting standards
employs a massive toroidal mains power source transformer—Model 600/1.3KVA, Model
300/700VA. Musicians and sound engineers are assured top performance of continous high
power output by an enormous heatsink output transistor—Model 600/6100cm^ Model
300/3700cm^
Superior reproduction is brought about through level adjustment of both channels by use of
detent volume calibrated in decibel increments.
And, to acknowledge receptivity, an LED level indicator blinks indicating peak levels. Featuring
peak hold log amp 1C indications are made in lOdB steps in the OdB to 40dB range.
Two red L.E.D. overload indicators on the front panel of the Model 600/300 utilize an exolusive
FOSTEX circuit. Whenever either channel of the 600/300 is driven into overload, a
corresponding indicator lights and remains lit for 0.25 seconds. These indicators, which actually
indicate loss of feedback, tell the operator that the amplifier is being overdriven, and can be
invaluable to the engineer or audiophile who must be sure that every component in his system is
producing a clean, distortion-free signal. An inadvertent short-circuited output (with signal) will
cause the L.E.D. to remain on until the short is removed.
The output stages of your amplifier use the most durable type of transistors available. These
large geometry, complementary power devices have large safe operating area and extended
power bandwidth. Electrostatic and other highly reactive speaker systems present no difficulties
for the Models 600/3(X).
All of the semiconductors in the output stage are in intimate contact with the heatsink. The bias
circuit is also mounted on this isotherm to provide rock steady bias stability with temperature.
The especially elaborated circuit design of models 6(X)/3(X) makes for an extremely low Total
Harmonic Distortion up to high frequencies, a large damping factor, and a greatly broad power
band width.
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