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





Hitachi HA-5300 amplifier


Features:
Dynaharmony system perfectly matched for music reproduction
Current mirror circuit in the Class A driver circuit
32-contact attenuator volume control for an accurately adjusted level control
Independent 3-stage adding gain selector for extended fine setting range
3-stage direct-coupled equalizer amplifier composed of 2 FET and 2 transistors with differential amplifier for first stage.
Easy listening comparison with speaker level control
Phono input capacitance selector switch
Low filter that reduces hum and rumble in the ultra-low frequencies without impairing the sound quality.
High filter that effectively cuts out noise produced from scratches on records and high frequency noise during AM and FM reception.
Tone defeat switch for instant flat characteristics
Protective circuitry for safety

 The new protection circuit of Hitachi
Muting Cuircuit
This set contains the muting circuit which cuts off the relay approx. 3,5 seconds after the power switch is turned on to eliminate the click sound generated by power switch operation.
ASO (Area of Safety Operation) detection circuit (output transistor protection)
This circuit functions to protect the transistors (Q711-Q714) from damage.
Especially when the voltage (Vce) between C - E of the output transistors is too high, the transistors are likely to be damaged when excessive collector current (Ic) flows. In this set, the protection circuit is designed to operate when Ic and Vce exceeds a certain value.
DC Voltage Detection Circuit (speaker protection)
When the DC voltege may appear at the speaker terminals during a malfunction, it may make speaker in trouble. To prevent this, the DC components in the output terminals are detected by the filter circuit of R818 and C811; when it is (+) voltage, Q803 is turned on, Q805 is turned off, and the speaker circuit is cut off by the relay; when it is (-) voltage, Q805 turns off by turning Q804, Q806 on and the relay is also operated. Incidentally, this protection circuit is reset automatically when the DC voltage disappears.
When the input terminals are touched by something or when some ultra low-frequency noise enters, speaker inputs are cut off temporarily but they reset automatically.

Specifications;
Power Section
Circuitry:  2-stage differential all-stage direct-coupled 4-power supply high-efficiency pure complementary OCL system (Dynaharmony System)
Dynamic Power Output:  260 W (IHF 8 Ω)
RMS Power (both channels driven):
60 watts per channel, min. RMS, at 8 Ω from 20 Hz - 20 kHz, with no more than 0,3% T.H.D.
75 W/ch + 75 W/ch (8 Ω, 1 kHz, 0,3% T.H.D.)
85 W/ch + 85 W/ch (4 Ω, 1 kHz, 0,3% T.H.D.)
Power bandwidth :  10 Hz -50 kHz
Total Harmonic Distortion (1 kHz, 8 Ω load):  0,05% (at rated output)
Intermodulation Distortion (60 Hz : 7 kHz = 4 : 1):  0,05% (at 1/2 rated output)
Damping Factor:  more than 40
Output Treminal:
Speaker :  A, B (4- 16 Ω), A + B (8 - 16 Ω)
Headphone :  more than 4 Ω
Speaker level Control:  B level is variable  -15 dB
Inpuut Sensitivity /Impedance:  1,0 V (55 k Ω)
Preamplifier Section
Circuitry: 
Equalizer amp. :  Differential 1-stage, 3-stage directly coupled
Control amp. :  NF type
Input Sensitivity/Impedance:
Phono 1, 2 :  2 mV/50 k Ω
Tuner, Aux :  100 mV/50 k Ω
Tape 1, 2 :  100 mV/50 k Ω
Phono Overload Level:  350 mV at 1 kHz, 0,3% T.H.D. (Phono 1, 2)
Output Level/Impedance: 
Tape 1, 2 Rec Out :  100 mV/1 k Ω
Frequency Characteristics:
Phono :  30 - 15,000 Hz (RIAA ±0,2 dB)
Tuner, Aux :  10 Hz - 50 kHz (+0 -2 dB)
Tone Controls:
Bass ;  ±8 dB at 100 Hz
Treble :  ±8 dB at 10 kHz
Filters:
Low :  20 Hz (12 dB/oct)
High :  8 kHz (6 dB/oct)
Loudness Control (Volume -30 dB):  +8 dB at 100 Hz , +4,5 dB at 10 kHz
Signal-to-Noise Ratio  (IHF, A network):
Phono 1, 2 :  75 dB
Tuner, Aux, Tape 1, 2 :  90 dB
Gain Selector;  -5, -10, -20 dB (addition type)
General
Semiconductors;  6 FETs, 44 Transitors, 43 Diodes
Power Supply:  120 V / 220 V / 240 V, 50/60 Hz
Power Consumption:  500 W at rated output
Dimensions (W x H x D):  435 x 166,5 x 391 mm
Weight:  12,3 kg (27, 1 lbs)

Nessun commento:

Posta un commento