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-5200

Pioneer SA-5200 - A compact, value-priced stereo integrated amplifier with advanced solid state circuitry and top versatility.

In the medium power and price range, few stereo amplifiers can match Pioneer's  SA-5200 for value and versatility. Designed for the person who is building his first set of home stereo components, this solid state amplifier offers the very latest circuit technology distinguished by superior stability and versatility. From the equalizer section to the power amplifier stages, the SA-5200 offers improved circuit design. The equalizer is unmatched in this price range for its precise RIAA equalization within +_0,5 dB as well as its ability for handling large inputs. In the power amplifier section, Pioneer has chosen complementary SEPP (Single-Ended, Push-Pull) ciruit with silicon transistors, offering ghigh efficiency and low distortion while delivering 13 watts + 13 watts of continuous power, both channel driven at 1 kHz into 8 ohms. The outstanding sound character of the SA-5200 makes it a value and a half, and the extent of this value is more than apparent when you price this amplifier. Another dynamic difference in true hi-fi components from Pioneer.

Circuit Description
Equalizer Amp
The signal from the Phono input terminal is fed to the input terminals of the equalizer amplifier stage, which employs a two-stage direct coupled circuit.
Since sufficient negative feedback from the second-stage collector is fed to the first-stage emitter, characteristics accurate to within ±0,5 dB on the RIAA curve can be provided. Compared with previous two-stage direct coupled circuits, this system makes for greater stability in the bass range and provides a surplus dynamic margin.
The amplified signal from the second-stage collector is fed to switch circuit-A ass'y through the Function Switch.

Control Amp
The signal selected by the Function switch is fed to the control amplifier through the Tape Monitor switch in switch circuit-A ass'y the loudness compensator circuit in switch circuit-B ass'y, and a potentiometer. The Tone Control circuit employs the nominal CR type configuration, and is connected after the one-stage amplifier. As in the bass and Theble tone controls, click-stop volume controls are employed, which provide high accuracy for flat frequency characteristics at the middle point of control knobs. The output of the control amplifier is fed directly to the power amplifier.

Power Amp
The power amplifier stage consists of seven transistors for each channel. It is composed of the thruout direct coupled  circuit with differential amplifier.
The signal from the control amplifier ass'y is fed to one base in the differential amplifier. The AC and DC negative feedabck from the output junction is fed to another base in the diffecrential amplifier so that overall stability is improved.
The differential amplifier output connects directly with the pre-driver base and amplifier. The signal from the pre-driver is amplifies by the driver and the power output stage, and fes to the speaker terminals through the Speaker switch in switch circuit-A ass'y.
Temperature compensation in the power amp ass'y is accomplished by a three-element varistor and the idle current adjustment by a semi-fixed variable resistor connected in series to the varistor.
Power transistor protection is accomplished by the fuse installed in series at the B-power circuit.

Power Supply
A full-wave rectifier circuits aupply all DC power. The rectified DC, with the ripple component eliminated by means of a 4,700 µF capacitor, is supplied for the output circuitry of the power amplifier circuit, and through CR filters for the other stages. The muting circuit eliminates the unpleasant noise usually heard when the power switch is turned On or Off. When the power switch is turned ON, the first-stage transitor Q1 in the power supply circuit is cut off immediately by the reverse bias caused  by a diode associated with the base.
When the power switch is turned OFF, the negative bias which has kept the first-stage transistor cut off is turned over to positive bias, and current entering the driver-stage transistor makes the second-stage transitor base connect to ground, the transitor cuts off the bias current entering the driver stage in the power amplifier ass'y. thus the amplifier stops working and unpleassant noise is eliminated.
A diode connected between the base and the emitter of the second-stage transistor permits discharge of the current charge in the power amplifier ass'y when the second-stage transistor is cut Off (when the power switch is turend Off).

Power Amplifier Section
Circuitry:  1st Stage Differential Amplifier, Dirct Coupled Quasi-complementary
 Continuous Power Output (both channel driven at 1 kHz):
15 W + 15 W at 4 Ω
13 W + 13 W at 8 Ω
Continuous Power Output (each channel driven at 1 kHz):
20 W / 20 W at 4 Ω
16 W / 16 W at 8 Ω
Power Output in 20-20,000 Hz (both channel driven):
10 W + 10 W at 8 Ω
Total Harmonic Distortion:
At continuous  Power  Output :  less than 0,8%
At 1 W + 1 W Power Output :  less than 0,2%
Intermodulation Distortion:
At Continuous  Power  Output :  less than 0,8%
At 1 W + 1 W Power Output :  less than 0,4%
Power Bandwidth (both channel driven IHF):  10 Hz - 40 kHz (THD 0,8%)
Output Speaker:  A, B, A+B (4 - 16 Ω)
Output Headphones:  4 - 16 Ω
Damping Factor:  more than 30 (1khz, 8 Ω)
 Preamplifier Section
Equalizer-amplifier:  2-stage Direct Coupled NFB type
Control-amplifier:  CR type
Frequency Response:
Phono (RIAA equalization):  30 Hz - 15 kHz ±0,5 dB
Tuner, Aux 1, 2; Tape Monitor :  15 Hz - 30 kHz ±1 dB
Hum and Noise (IHF, Shsort-circuited, A-Network):
Phono :  more than 70 dB
Tuner, Aux 1,2; Tape Monitor :  more than 90 dB
Input Sensitivity/Impedance:
Phono Mag :  2,5 mV/50 k Ω
Phono Overload Level :  100 mV/280 mV (rms/p-p)
Tape Monitor:  150 mV / 100 k Ω
Tape Rec/Pb (DIN  connector):  150 mV/100 k Ω
Aux 1, 2  :  150 mV/100 k Ω
Tuner :  150 mV/100 k Ω
Output Level/Impedance:
Tape Rec :  150 mV
Tape Rec/Pb (DIN connector)  30 mV/80 k Ω
Bass Control:  +12 dB; -10 dB at 100 Hz
Treble Control:  +9,5 dB; -10,5 dB at 10 kHz
Loudness Contour (-40 dB position):  +10 dB at 100 Hz ; +6 dB at 10 kHz
Power Requirements;  AC 120 V 60 Hz or AC 110 V , 120 V, 130 V, 220 V and 240 V 50/60 Hz (switchable)
Power Consumption:  85 W max
AC Outlets:  1 Switched, 1 Unswitched
Semiconductors:  22 Transitors; 7 Diodes
Dimensions (W x H x D):  415 x 132 x 328 mm (16-5/16" x 5-3/16" x 12-15/16")
Weight:  7,2 kg (15 lb 13 oz)

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