Accuphase P 300 Brochure

Page 2

DUAL CHANNEL

- WCCUP

It is a mistake to calculate the value of a power amplifier solely in terms
of $/power or cost/power. Other more important factors should also be
considered to assess its overall value such as those power qualities like
low distortion, well-regulated power supply and power bandwidth, as
well as additional functions and appearance values.

Music delivered through a good power amplifier should have an extra
quality of deep, rich bass and the subtle nuances of inner musical fabric
which stir and warm the soul with emotion. A good power amplifier must
also have the range to reproduce precisely the softest to the loudest
passages of music, and, at the same time. it must be able to handle,
without distorting, all the large input amplitudes that may be involved.
The P-SDO can coast through all of these requirements without strain due
to its large, heavy-duty power transformer and 2 x 40,000 uF filter
capacitors, its all-stage. push~pull circuit configuration, and well selected
and thoroughly tested parts. Prepare to enjoy exciting music with the
Accuphase P-300 which can deliver it!

EVERY STAGE IS PUSH-PULL DRIVEN

Every stage, from input to output, is a direct-coupled, extravagant,
push-pUII lineup. As a result, a big improvement in characteristics before
negative feedback application ensures low distortion and dependable
operation with any impedance and type of speaker, (single, two»way,
3-way or static electrical) throughout the audio range, from low to high
powers.

TRIPLE PUSH-PULL OUTPUT STAGES

Six heavy-duty power transistors are used in the direct-coupled,
Complementary-Symmetry circuit output stage of each channel. A large,
efficient heat sink is provided to ensure adequate heat dissipation when
the P800 is required to deliver full power output continuously.

HEAVY DUTY STABLE POWER SUPPLY

The stable power supply of the P-300 which can meet the heavy
requirements of 400 watts of power into 4 ohms without strain, also can
maintain, with ease, well regulated supply voltages against varying load
conditions created by rapidly changing input signals. Even for fff, each
music part is separated smoothly, and there is no awareness of
muddiness.

CLOSELY SELECTED PARTS

It is a well known fact that different parts can be responsible for
differences in sound quality, even from exactly the same amplifier
circuit. This is due to the fact that the parts themselves often possess
certain electrical characteristics which have no relation to their designat-
ed function.

All parts, therefore, are selected carefully with "performance first" in
mind, and they are subjected to severe durability and other tests to
determine how their characteristics might affect sound quality.

DEPENDABLE SPEAKER PROTECTION CIRCUIT

Mistakes in speaker connections that cause short circuited outputs or
similar troubles will disconnect the speakers automatically by relay
action from this amplifier to protect expensive speakers from damage. in
such cases, the power meter lamp will flash on and off successively as a

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warning signal. As soon as the trouble is corrected, the lamp will again
glow steadily, and normal operation will resume automatically.

BANDPASS FILTERS

undesirable turntable rumble and subsonic tone arm resonance vibrations
that enter the input may appear as intermodulation distortion in the mid
and high frequency ranges. Ultrasonic vibrations that enter the input can
also mix with high frequency range signals to cause "beat" interference
and overheating of transistors Bandpass filters, with a sharp cut-off
characteristic of 18dB/oct, are provided to eliminate these undesirable
signals below 17 Hz. and above 24 kHz. These filters can be switched ON
or OFF with a control available on the front sub-panel.

LARGE SIZE POWER METERS

Large size power meters indicate power output in dB. Switch selection of
three ranges, 0 dB, -10 dB and -20 dB. permit both low and high power
measurements. A 0 dB reading indicates power output of 150 watts into
8 ohms when the meter range switch is set to 0 dB. J
PLENTY OF INPUT/OUTPUT TERMINALS

Plenty of outputs are available to which four pairs of stereo speakers can
be connected. and switch selected. Accommodations for two pairs of

input systems are also provided, and they too can be switch selected.
Jacks are available on the front sub-panel for one pair each of these

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