Superscope A-245 - Alignment Procedure; Setting Up for Alignment; Circuit Board Diagrams; Tone Control Block Diagram

A-245 (E)
ALIGNMENT PROCEDURE
1. Set the volume contro! at maximum, bass, treble 2. Connect 8 ohms dummy load resistors (10—20W,
and balance controls at mechanical center position, non-inductive preferably) to each R and L channel
speakers switch in the position “MAIN” while “MAIN” output terminals of the unit.
switching the tape monitor and loudness control
switches off.
(Selector Switch in the position ““AUX’’)
Signal Sou rce Indicator
Gradually increase output level of the audio generator
and adjust. R161 and R162 for symmetrical clipping
level.
A A=B
Audio Generator
to AUX terminal
Oscilloscope to
output terminals
Adjust R166 and R167 for not having any evidence of
crossover distortion at 500mW output.
Caution: Avoid excessive bias current (10mA at no signal).
CIRCUIT BOARD DIAGRAM (TOP VIEW)
Audio Amp. Block
2