TA6300 6 Channel Power Amplifier
2
SECTION 1
Introduction
T he SMART model TA6300 is a professional six-
channel amplifier featuring DC protection, quick
interconnect with SMART companion products,
soft clip speaker protection and massive heatsink
extrusions with internal D.C. fan assist to make
sure your amplifier stays cool even when the
music is hot. TA6300 delivers 200 watts per
channel into 8 ohms on five channels simulta-
neous with 400 watts into 4 ohms on the sixth
(subwoofer) channel.
Circuit Description
To assure absolute long-term reliability, the
output section of each channel incorporates
multiple Motorola Power T ransistors, which
provide three times the amplifiers rated power in
watts of dissipation per channel. The output
stage is arranged in a fully complementary
format for class AB/2 operation. T he bias current
is evenly distributed among all output devices.
Bias thermal compensation is accomplished by
thermally mating a bipolar semiconductor
junction to the heat-producing output device.
T riple diffused high power driver transistors are
employed along with high speed, high voltage
silicon annular devices for the pre-driver and
inverter stages. Utilization of these components
provide the required separation of FT break
points for absolute stability . Fully complemen-
tary drive and loading is utilized throughout.
Only 20dB of negative feedback is used to
reduce forward transfer distortion to minimum
levels. VI type energy limiters are incorporated
for short circuit protection of the amplifier. Due
to the unusually large safe operating area of
output stage, the limiters do not actuate until
driving a forty-five degree reactive load of under
2 ohms at full power.
Construction
The amplifiers are designed on an all-modular
concept permitting rigorous pre-assembly mod-
ule testing and maximum service accessibility.
Each functional module is fully tested before
final assembly. Although components of the
highest quality are used throughout, each ampli-
fier is burned in, prior to shipment, at the worst
case operating point to eliminate any possibility
of component malfunction. All chassis compo-
nents are precision machined from high quality
aluminum and 16-gauge sheet steel stock. T he
entire package concept is directed toward
maximum efficiency of space and structure,
accounting for the compact size and light
weight.
SECTION 2
Installation
All SMART amplifiers are designed for mounting
in a standard 19-inch equipment rack, or many
of the 19-inch rack type portable cases avail-
able. T he T A6300 require 7 inc hes of vertical
panel space, with 15" inches required behind
the panel. Total depth including the handles is
16-3/8" inches. F ront panels are machined from
solid aluminum stock, with a black powdercoat
finish and sturdy rack mount handles.
Placement of the amplifier is not critical for
normal operation, provided sufficient airflow is
allowed to reach the heatsink array. If the unit is
to be placed on a shelf, or a similar unenclosed
area, allow four inches of clearance behind the
fan air intake to permit airflow through the arra y .
If the amplifier is to be mounted in an equipment
rack or cabinet with heat producing equipment,
be sure that environmental operating tempera-
tures do not exceed 55 degrees C (131F).
Should overheating occur because of inad-
equate ventilation, the temperature protection
circuitry will automatically protect the amplifier .
When a safe operating temperature is restored,
the amplifier will return to normal operation.