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 speakersare 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-250

 High power output of 100 wats per channel into 8 ohms with clean sound quality at all listening levels. This high power capability, with distortion at less than 0,1% from 20 to 20,000 Hz is fully guaranteed. Heavy duty power transistors in a parallel push-pull drive output stage and large heat sinks back up this Accuphase warranty.
High power amplifiers need an especially reliable power supply that must not only provide the energy to drive the speakers but the capacity to store and deliver adeguate power to trace the sharpest fluctuating signal. The P-250 has just such a power supply with an oversize power transformaer and two giant 20,000µF filter capacitors that can easily supply the energy required to deliver 280 watts of continuous power into 4 ohms. A severe rise in distortion when  volume is reduced to low levels is a problem with many high power amplifiers, but not so with the P-250 in which such distortion has been eliminated to the lowest possible limit. It permits enjoyment of clean, clear pianissimo passages at All volume levels.
 Speaker Damping Control enhances characteristic tonal qualities speakers.
The damping factor of solid state amplifiers is generally very large and ideal for damping the speakers. However, some speakers require en amplifier with a low damping factor to reproduce rich, full-bodied sound. The P-250 has a Speaker Damping Control which permits choice of three damping factors and induces maximum potential performance from any speaker. Damping factor with an 8 ohm  load becomes more than 50 when this control is set to Normal. Likewise, it is 5 at Medium position, and 1 at at Soft position. It enables choosing the speaker sound that one prefers.

Foolproof protection Circuit safeguards power transistors and speakers.
The P-250 has a built-in Protection Circuit which guards against damage to speakers or power transistors in case of shorts when the speakers are connected, or when abnormally low impedance output load connections are made. If the speakers are shorted, this circuit automatically cuts them from the amplifier.
 Large size power meters.
Large size power meters indicate power output in decibels (dB). The meters also provide indications to read output power level directly in watts. Switch selection of three ranges, 0 dB; -10 dB and -20 dB, permit both low and high power measurement. At 0 dB reading indicates power output of 100 watts into 8 ohms when the meter range switch is set to 0 dB.
 Plenty of Input / output terminals.
Plenty of outputs are available to which three 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 selscted. One pair of input system is provided on the front sub-panel for easy accessibility.

Specifications
Power Output (both channel driven from 20 Hz to 20,000 Hz with no more than 0,1% THD):
140 watts per channel, min. RMS, at 4 Ω
100 watts per channel, min. RMS, at 8 Ω
50 watts per channel, min. RMS, at 16 Ω
Total Harmonic Distortion (from 20 Hz to 20,000 Hz at any power output from ¼ watt to rated power):
4 Ω : 0,1% max.
8 Ω : 0,1% max.
16 Ω : 0,1% max.
Imtermodulation Distortion:  will not exceed 0,1% at rated power output for any combination of frequencies between 20 Hz and 20,000 Hz
Frequency Response:
20 Hz to 20,000 Hz : +0; -0,2 dB at rated power output
5 Hz to 90,000 Hz : +0; -3 dB at rated power output
Slewing Rate:  more than 15 V/µS
Damping Factor (at 8 Ω load, 20 Hz to 20,000 Hz ):
With "Speakr Damping" switch set to:
"Normal" : 50
"Medium" : 5
"Soft" : 1
Input Sensitivity/ Impedance:
1,0 Volt, 100 k Ω, for rated output at the max. Level control
Hum and Noise:  94 dB below rated output
Power Level Meter
Meter is calibrated to read 0 dB when amplifier produces 100 watts into 8 Ω load.
Meter Range switch is provided to increase meter sensitivity by 10 dB or 20 dB
Output Load Impedance:  4, 8 and 16 Ω
Audio Bandpass Filter:
Cut off Frequency;
LOW : 17 Hz 18 dB/oct
HIGH : 24 kHz 18 dB/oct
Headphone Jack:  For listening with low impedance (4 - 32 Ω) dynamic stereo headphones
Power Requirement:  100 V; 117 V; 220 V; 240 V, 50/60 Hz
Power Consumption:
70 watts at zero signal output
375 watts at rated power output into8 Ω load
Semiconductor Complement:  36 Transistors, 34 Diodes
Dimensions (W x H x D):  445 x 152 x 355 mm (17 ½" x 6" x 14")
Weight:  19,5 kg (42,9lbs) net

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