Heathkit AS 1363 Schematic

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Page 25

CIRCUIT DESCRIPTION

Each speaker is electrically isolated from the others.
Therefore, this circuit description will cover each
speaker as an individual circuit with a common in.
put. Rotor to the Schematic diagram while you read
the Circuit Description.

WOOFER

Inductor Ll passes the frequencies below 750 H7. to
the woofer and attenuates the frequencies abovt: 750
Hz at the rate offs dB/oclave, Because the voice coil of
the woofer is inductive, capacitor C1 and resistor R1
are needed to maintain a true o-ohm load for inductux
L1. Fuse Fl prOIBdS the woofer speaker.

MIDRANGE

Capacitor (:2 rolls ott ireouencies below 750 Hz at a
rate uf6 clB/octave and passes frequencies above 750
Hz. The speaker is allowed to roll off above 4000 Hz
with no electrical crossover. Switch SM and R2 are
used for series attenuation inthe midrange frequency
area. Fuse F2 protects the midrange speaker.

TWEETER

Capacitor C3 and inductor L2 form a high-pass filter
with a 12 dB/octavarull»offal 4000 Hz. Resistor R3 is a
series attenuator that matches the level of the tweeter
to the rest of the system. Switch swz and resistor R4
attenuate the tweeter 3 dB Fuse F3 protects the
tweeter speaker.

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MODEL AS-1363

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