What is stereo?

There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.

H.H. Scott '59

Accuphase P-800 (1988)

Balanced Stereo PowerAmplifier
Completely balanced powerful output stage consisting of two sets of 7 parallel push-pull transistor pairs
Outstanding low-impedance drive capability
Separate power supplies for left and right channels
Balanced input

Ever since the advent of pulse coding method to record electric signals, the world of reproduced music is about to underego significant changes, because the digital recording technology has brought about substantial improvement in the reality of the reproduced music. Moreover, minute and subtle reverbration components, which are essential to reproduce the atmosphere of the original sounds, can now be recorded with utmost accuracy.

Needless to say, accurate transmission of signals is indispensable in the reproduced sound fields; otherwise, we cannot even appreciate the reproduced music and in the worst case, we may not be able to perceive what we listen to as music but nothing more than collection of noises. Equally important for reproducing music, however is an amplifier that can correctly amplify even reverbration components to reproduced music, as if the music were being played by an orchestra right in front of you. Without such an amplifier, the atmosphere of beautiful and elegant music cannot be reproduced. It is therefore vital for a power amplifier to be able to yield power of high amplitude and, at the same time, to amplify minute signals superimposed on the electric signals it amplifies, with high fidelity. However the power an amplifier can produce and its fidelity are, in many case, in a mutual contradictory relation, and the higher power an amplifier can produce, the lower its fidelity in reproducing minute signals and reverberation components. The P-800 which was developed with Accuphase's technology that has already produced a superb monophonic amplifier, M-1000 is an exceptional power amplifier in this respect as it can yield a power of as high as 600 watts (into 4 ohm loads), but reproduce even reverberation components with high fidelity, which is not possible with most of the amplifiers on the market today. Its uses two power units in bridged configuration, forming a totally balanced amplifier, meticulous attention has been paid to every detail, and original Accuphase technology is used throughout, with the aim to improve quality especially at low signal levels.

The impedance of loudspeakers on the market varies considerably, ranging from about 2 ohms to 16 ohms. With a direct-coupled amplifier, driving such a wide impedance range with equal aplomb is almost impossible. An output stage designed for optimum performance at 2 ohms will deliver less power into 8 to 16 ohms. Conversely, the performance of an amplifier optimiozed for about 4 to 8 ohms suffers at 2 ohms and it will not be capable of driving 1-ohms loads.
The P-800 incorporates a special design to deal with a wide range of load impedances. The applied voltage of its output devices can be switched to a lower value, to provide the high current capability required by low-impedance loads. This results in a truly amazing guaranteed rating of 600 watts into 1 ohm and 400 watts into 2 ohms, with undiminshed sound quality. To achieve such stunning performance the output stage of each power unit employs two sets of seven parallel push-pull pairs of wide-band transistors with a maximum power dissipation of 130 watts each. This amounts to 14 pairs or 28 transistors per unit, totaling a maximum powe dissipation of 3,6 kilowatts. These truly astounding figures testify to the no-holds-barred Design approach of the P-800.

To let you monitor its performance, the P-800 incorporates two symmetrically arranged analog level meters.
The beautiful and simple elegance of this amplifier's external appearance belles its awesome performance. But when turned on, it speaks unmistakably through music.

Totally balanced construction with two separate power units for ultimate sound quality
Accurate reproduction of sound field with two independent power supplies
Ultra-powerful output stages consisting of two sets of seven parallel push-pull transistor pairs each
Excellent low-impedance drive capability - 600 watts into 1 ohm, 400 watts into 2 ohms
Cascode differential push-pull input stage tuned for perfection
"Cascode push-pull + MOSFET cascode pus-pull" drive stage for minimum distortion at low levels and superior high-range stability
Large analog power meters reading -60 dB to +3 dB
40-kilohm balanced input and 20-kilohm unbalanced photo jack

Performance Guaranty
All Accuphase product specifications are quaranteed as stated
Continuous Average Power Output (20 -20,000 Hz):
Normal load impedance operation (THD 0,01%)
600 W/ch into 4 ohms
400 W/ch into 8 ohms
200 W/ch into 16 ohms
Low load impedance operation (THD 0,05%)
600 W/ch into 1 ohm
400 W/ch into 2 ohms
200 W/ch into 4 ohms
Total Harmonic Distortion:
0,05% with 1 to 4 ohmload
0,01% with 4 to 16 ohm load
Intermodulation Distortion: 0,003%
Frequency Response:
20 to 200,000 Hz ±0 dB (for rated output, level control at max.)
0,5 to 150,000 Hz +0, -3,0 dB (for 1 watt output,level control at max.)
0,5 to 80,000 Hz +0, -3,0 dB (for 1 watt output, level control at -6 dB)
Gain: 28,0 dB
Output Level Impedance:
4 to 16 ohms in Normal load impedance operation
1 to 4 ohms in Low load impedance operation
Damping Factor (EIA, 50Hz): 200
Input Sensitivity:
Normal load impedance operation
2,25 V for rated output into 8 ohms
0,12 V for 1 watt output into 8 ohms
Low load impedance operation:
1,13 V for rated output into 2 ohms
0,06 V for 1 watt output into 2 ohms
Input Impedance:
Unbalanced: 20 kilohms
Balanced: 40 kilohms
Signal-to Noise Ratio (A-weighted):
125 dB with input shorted at rated output
95 dB with 1 kilohm input termination at 1 W output
Power level Meter:
Logarithmic compression scale, peak reading -60 dB to +3 dB and direct watt-reading scale
Semiconductor Complement:
158 transistors, 20 FET's, 15 ICs, 158 diodes
Power Requirements:
100/117/220/240 V, 50/60 Hz AC
Power Consumption:
110 watts + 110 watts idle
610 W + 610 W in accordance with IEC-65
740 watts + 740 watts at rated power output into 8 ohms
Dimensions (W x H x D): 481 x 239 x 489 mm (18¹⁵/₁₆ x 9¹³/₃₂ x 19¼ inches)
Weight: 47,2 kg (103,8 lb) net, 55,2 kg (121,4 lb) inshipping carton

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