Specifications

TONE AI\4PLIFIER
The TONE A[,4PL|FlER's
circuitry uses a con
tinuouslv variable
R-C {eedback type configura
tion. Figure 11
shows
the frequency
response
curves for
maximum boost
and cut
{or each
control. The signal
from
the TONE A[4PLl
FIER
feeds the hillow filter circuil when
the
Hi
FILTER or the LOW
FILTER
pushswilch
is
depressed.
H|-LOW FILTERS
Fiqure 12
shows the
{requency response curves
resulting {rom
use
of
the
two filters.
OUTPUT STAGE AND
PROTECTIVE
CIR.
CUITS
The
pr+driver
circuit ampli{ies the signal
from the
Hi/LOW FILTER to sufticient levels to drive
the
output stages. Beyond the input of the
predriver
circuil the amplifier stages
are
direct'coupled
through to the loudspeakers
(and
headphones)
providing
inslantaneous
recovery from
overdrive
or
short
circuit condilion!. ThF
oLrrpul slage consists
of a
pair
of
push
p!ll,
complementary symmetry
transistors
(PNP,
NPNI. The electronic
protective
circuit senses the
peak
output current and
limits
the current to the driver' transistors at
a safe,
predetermined
value. This current I imiting
protects
the driver and output transistors under
overdrive
and short circuit conditions and
effectively
prevents
the driver and output transistor
from
exceeding sa{e
operating
conditions.
This in-
stantaneous actinq
safety
circuit
gives
constant and
unobtrusive
protection
wiThout causing annoying
program
interruptions.
CAUTION:
The
loudspeaker
terminals
of one
channel
should
never
be connected
directly in
parallel
with any other. Any resulting damage is
not covered under the warranty,
15