Adcom GFA 535 Setup

Page 2

INTRODUCTION

The GFA 535L is identical in all respects (power output, operating
parameters, sensitivity, operation, installation, connections, etc.)
to the GFA-535. except for the addition of the two level controls on
the front panel directly above the L and R lNSTANTANEOUS
DlSTOFlTlON ALERT LEDs. Therefore, it is very important that
you read thoroughly the OWNER'S MANUALfor the GPA-535, as
well as this addendum, before connecting or attempting to operate
the GFA-535L.

INPUT LEVEL CONTROLS

The input-level-control design in the GFA~535L preserves the
22,000 ohm input impedance of the GPA-535 and remains at
22,000 ohms regardless of the position of the level controls. The
design was carefully integrated into the input circuitry of the GFA-
535L to insure that no degradation in performance would occur
with different settings of the level controls. All operating
parameters will remain the same at any position of the level
controls (distortion, frequency response, bandwidth, damping,
etc.). The only specification which will vary is the input sensitivity
of the amplifier. Whereas the input sensitivity of the amplifier is

1 volt RMS, for full output, at the maximum clockwise position of
the level controls, this sensitivity will be proportionately reduced
as the level controls are turned counterclockwise from their
maximum "on position. That is, as the level controls are turned
counterclockwise from their full "on" position (maximum
clockwise), input levels higher than 1 volt HMS will be required to
reach maximum output, and, therefore, the level at which
loudspeakers connected to the amplifier will play will he reduced
proportionately.

The input level controls are easily and readily adjusted via a
medium~sized, flat-bladed screw driver, or a "dime". Coins larger
than a dime will not fit the slots on the level controls and, if used,
will "nick" and mar the finish on the shafts.