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

Pioneer SA-7500

 Pioneer belives in music. And when a Pioneer product like the SA-7500 integrated stereo pre/main amplifier reaches the production stage after months of refinement, you can be sure it stresses musicality above all else. Handling creative musical information requires as much or more precision as is needed in today's  most sophisticated measuring apparatus and communications systems. This is why Pioneer is not siply an expert in modern electronics but a respected high fidelity audio specialist as well.
The SA-7500 bears this out. It has all the latest circuits and facilities, including a precision phono equalizer and extra-versatile tone control section. And it has a higher power rating than most pre-main models in its class. Continuous power output of 40 watts per channel, min. RMS at 8 ohms from 20 Hz to 20 kHz with no  more than 0,3% total harmonic distortion. Yet feature for feature, it's priced less than most of the competition. 
Power Amplifier - The SA-7500 employs high reliability NPN and PNP silicon power transistors. Together with the differential first stage, all stages are direct coupled in a pure complementary OCL circuit configuration. Careful circuit design and selection of components results in a wide output bandwidth.

Precision Tone Control Functions -  Conventional Bass and Treble controls are each provided with Turn Over switches for selecting the frequencies at which the controls take effect. A convenient Tone switch is also included which permits a flat frequency response to be obtained regardless of the tone control settings.
Close RIAA Equalization - RIAA deviation, which governs record playback fidelity, is reduced to very close tolerance by strinently selected equalizer elements. A dual DC power supply system is also employed to provide increased acceptable input volume, resulting in expanded dynamic range and faithful record performance at low distortion.

Protection Circuit - Electronic circuitryand a relay are combined in a fast action protection circuit which guards transistors and speakers from damage in the event of defective connections, such as speaker terminal shorting. When DC current appears in the output, the output circuit is instantly opened. The protection circuit also performs a muting function when the power switch is operated.
Power Amplifier Section
Circuitry:  1-stage differential amplifiers - Direct coupled OCL
Power Output (20 - 20,000 Hz with no more tha 0,3%THD):
40 watts per channel min. RMS at 8 Ω
45 watts per channel at 4 Ω
Continuous Power Output (at 1,000 Hz Both channel driven):
45 watts per channel at 8 Ω
50 watts per channel at 4 Ω
Total Harmonic Distortion (at 20 Hz - 20,000 Hz):
Continuous Rated Power Output :  no more than 0,3%
20 watts per channel Power Output, 8 Ω :  no more than 0,05%
1 watt per channel Power Output, 8 Ω :  no more than 0,05%
Intermodulation Distortion (at 20 Hz - 20,000 Hz ):
Continuous Rated Power Output :  no more than 0,3%
20 watts per channel Power Output, 8 Ω :  no more than 0,05%
1 watt per channel Power Output, 8 Ω :  no more than 0,05%
Frequency Response:  10 Hz to 80,000 Hz  +0 -1 dB
Input Sensitivity/Impedance
Power Amp In :  1 V/50 k Ω
Speaker :  A, B, A + B
Headphone : Low impedance
Damping Factor (20 Hz - 20,000 Hz, 8 Ω):  25
Hum and Noise (IHF, Short-circuited A Network):  100 dB
Preamplifier Section
Equalizer Amplifier :  3-stage direct-coupled amplifier
Control Amplifier : 2-stage direct-coupled with 1 FET NFB type
Input Sensitivity/Impedance:
Phono 1 :  2,5 mV/50 k Ω
Phono 2 :  2,5 mV/50 k Ω
Mic "  7,5 mV/85 k Ω
Tuner :  150 mV/50 k Ω
Aux :  150 mV/50 k Ω
Tape PB 1 :  150 mV/50 k Ω
Tape PB 2 (DIN connector) :  150 mV/50 k Ω
Phono Overload level (THD 0,1%)
Phono 1 :  200 mV (1,000 Hz)
Phono 2 :  200 mV (1,000 Hz)
Output Level Impedance:
Tape rec 1 :  150 mV
Tape rec 2 (DIN connector) :  30 mV/80 k Ω
Pre Out :  1 V/1 k Ω
Total harmonic Distortion (at 20 Hz - 20,000 Hz):  no more tha 0,05%
Frequency response:
Phono (RIAA standard):  30 Hz - 15,000 Hz ±0,3 dB
Tuner, Aux, Tape PB :  10 Hz - 50,000 Hz +0 -1 dB
Tone Control
Bass :  ±7 dB (100 Hz)/ ±11 dB (100 Hz); Turnover Frequency 200 Hz / 400 Hz
Treble :  ±7 dB (10 kHz)/ ±11 dB (10 kHz), Turnover Frequency 5 kHz / 2,5 kHz
Low :  30 Hz (6 dB/oct)
High :  8 kHz 96 dB/oct)
Loudness Contour (volume control set at -40 position):
+8,5 dB at 100 Hz
+4 dB at 10 kHz
Hum and Noise (IHF, Short-circuited, A Network):
Phono 1, 2 :  70 dB
Mic : 65 dB
Tuner, Aux, Tape PB :  90 dB
Muting:  0, -20 dB
FETs :  2
Transistors :  35
Diodes :  21
Power Requirements:  110 -120 V / 220 -240 V 50/60 Hz
Power Consumption:  200 watts (at 110-120 v AC)
Dimensions (W x H x D):  420 x 150 x 345 mm (16-9/16' x 5-7/8" x 13-9/16")

Weight (net):  12 kg (26 lb, 7 oz)

Nessun commento:

Posta un commento