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| Pioneer C-77 |
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| 120,000yen(around the 1980 time) |
@
The stereo preamplifier
which improved the property of each circuitry and aimed at coexistence of
multifunction nature and a tone quality.
The equalizer circuitry serves
as circuitry of 3 steps of first rank differentials hardwired-connection Class-A
SEPP by }2 power source.
The styrene capacitor of 2% of the error was
combined with the precision nichrome vapor-deposition metals skin membrane
resistance of 1% of the error, and the frequency characteristic of less than
}0.2dB is secured to the NFB element in all the bands (20Hz - 20kHz).
In
order to reproduce the dynamic range minced by the record, the high voltage of
}48V is impressed to an equalizer circuitry.
Also when the cartridge
from which an Output voltage differs is connected to two phone input terminals,
the level control to a phone of -12dB (Input sensitivity of 2.5mV - 10mV) is
possible for two so that level doubling may be made.
In a special 4-unit volume, the scheme with which -6dB controls the amount
of NFB and -6dB to -12dB controls an Output voltage is adopted, when it
extracts to -6dB or more, a maximum permissible input becomes large with
about double 1V, and a using of a high-output cartridge is also possible.
The original
twin tone control of Pioneer is adopted as a tone circuitry.
This circuitry
is the scheme equipped with the control of 50Hz super-low-pass one and a 20kHz
super-high region as a subcontrol besides a main control of Bass100Hz and
Treble10kHz,Since a total of 5929 sorts of curves can be made combining a main
and a factice, the advanced control united with the property is enabled.
By the decibel window of 22 contacts, the method of an attenuator with
the precision of a window error of }0.2dB and a right-and-left interlock error
of less than 0.2dB was made the volume, and it takes it.
Furthermore, the
volume has adopted the special 4-unit type, in order to carry out an attenuate at two places, the preceding paragraph of control amplifier, and a subsequent
stage, a noise decreases and its SN at the time of a using is usually improving.
Control functionalities, such as an attenuator of -15dB-30dB of 0dB, a
high cut-off filter, two tapes duplicate switchpoints, and a tone switchpoint, are carried.
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.JPG)
| Form |
Stereo preamplifier |
| Circuit system |
Equalizer-amplifier part: 3 steps of first
rank differentials hardwired-connection final-stage Class-A SEPP
Control
amplifier part: 3 steps of first rank differentials hardwired-connection
final-stage Class-A SEPP |
| Input terminal |
Phono1:2.5mV/50kohm
2:2.5 mV - 10mV of Phono / 50kohm
MIC: 2.5mV / 50kohm
Tuner, AUX1, 2:150mV / 100kohm
Tape Play1, 2:150mV / 100kohm |
Phono maximum permissible input
(THD
0.05%, 1kHz) |
Phono1:500mV
Phono2:500mV-1000mV
|
| Output-terminal |
Tape Rec1, 2:150mV / 2.2kohm
Output(RL:50kohm): 2V/600 ohm, 7V/600 ohm |
| THD (20Hz - 20kHz) |
0.03% (2V output)
0.05% (7V output)
|
| Frequency characteristic |
Phono1, 2:20Hz-20kHz}0.2dB
Tuner, AUX, and TapePlay:10Hz-70kHz+0 -0.5 dB |
SN ratio (IHF, A network)
Short circuit
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Phono:74dB
Tuner, AUX, TapePlay: 90dB
|
Tone control
(1.5dB step) |
| Bass |
Main: }7.5dB (100Hz)
Sub: }4.5dB (50Hz)
|
| Treble |
Main: }7.5dB (10kHz)
Sub: }4.5dB (20kHz)
|
|
| Filter |
Low: 15Hz, 30Hz (12 dB/oct)
High: 12kHz,
8kHz (12 dB/oct) |
| Attenuator |
0, -15, -30dB |
| The semiconductor used |
IC: Two pieces
Transistor: 50 pieces
Diode, other:31 piece |
| Supply voltage |
100V, 50Hz/60Hz |
Power consumption
(Electrical Appliance and Material Control Law) |
17W |
| Dimensions |
Width 480x height 186.5x depth of 365mm
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| Weight |
11.2kg |
| EIU specification rack mounting unit
|
4U |
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