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)
