Audio Database

The

SANSUI AU-777
57,700yen(May, 1967 release)

Description
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The Integrated Amplifier which adopted the silicon transistor.

C and E splitting type phase inversion circuitry were used for the output stage, and all the silicon transistor-ization is realized.
Thereby, the outstanding high region property and linearity by a silicon transistor have been obtained.

All the amplifying circuits from the first rank to the final output stage are constituted from NF amplifier, and the frequency characteristic, distortion, and SN are improved.

The two which use attenuator of 3dB step step NF type is adopted as a tone control.
Moreover, a completely flat property is acquired in the tone center.

The pure electronic formula PSC (protection) circuitry original with an SANSUI is adopted so that a power transistor may not be damaged, even when an output-terminal short-circuits.
In AU-777, the double safety interlock which secures a safeness more combining an immediate judgment fuse in a power transistor further is adopted.

A preamplifier part and a power amplifier part can be used separately.
For this reason, if channel dividers are connected to a preamplifier output-terminal and power amplifier is added, it can use also as a multi-amplifier system.

Two Phono input terminals are carried, Phono1 is designed by 47kohms and Phono2 is designed by 100kohms.
Thereby, it can use properly by the load resistance of a cartridge etc.

The center channel output-terminal is carried and two circuitries of a flat output and a 200Hz high cut output are prepared.

The tapes equalizer which can be changed according to the speed of a tapes is carried.

The low filter and the high filter of CR feedback scheme are carried.

Functionalities, such as a loudness control, a tapes monitor, a presence switchpoint, a headset jack, and a muting switch, are carried.


Rating of a mode
Form Solid-state Integrated Amplifier
<Power amplifier part>
Stereo effective output (both channel drive) 25W+25W}1dB
Effective output 30W/30W}1dB
Music power 70W}1dB
THD 0.5% or less
Cross modulation distortion (60Hz:7kHz=4:1) 0.8%
Power Band Width (IHF, 0.5% of distortion) 20Hz - 50kHz
Frequency characteristic 20Hz-100kHz}1dB (at the time of a normal output)
Channel separation 50dB
A hum and a noise (IHF, closed circuit) 100dB
Input sensitivity (an effective output, 1kHz) 1V
Input impedance 300kohm
Load impedance 8ohm-16ohm
Dumping factor 24 (8ohms)
Center channel output Flat output: 9.5V
High cut output: 1V (fo = 200Hz)
Presence 50Hz, +6dB (fo = 125Hz)
<Preamplifier part>
Output voltage Maxima: 5V
Rate: 1V (180ohms)
THD 0.1% (Output-power voltage)
Frequency characteristic 20Hz-70kHz+0.5dB--1.5dB
A hum and a noise (IHF) Phono1, 2:80dB (closed circuit)
Tape Head 19cm/sec: 85dB (closed circuit)
AUX1, 2:85dB (open circuit)
Input sensitivity/impedance (1kHz) Phono1:2mV/47kohm
Phono2:2mV/100kohm
Tape Head 19cm/sec:1.5mV/200kohm
Tape Head 9.5cm/sec:1.3mV/200kohm
AUX1, 2, Tape Monitor:140mV /, 100kohm
Sound-recording output (Tape Rec) Phono1, 2: It is 37dB (70 times) to an input.
Tape Head 19cm/sec: It is 39dB (90 times) to an input.
Tape Head 9.5cm/sec: It is 41dB (110 times) to an input.
Tone control Bass: 20Hz}15dB (3dB step)
Treble: 20kHz}15dB (3dB step)
Loudness control (Volume-30dB) 50Hz : +8dB, 10kHz : +5dB
A high filter 20kHz-22dB
A low filter 20Hz-21dB
Muting - 20dB (20Hz - 20kHz)
Mode switch Stereo (Norm, RX-Net Rev)
Mono (L, R)
<Synthesis>
The semiconductor used Transistor: 26 pieces
Diode: Eight pieces
Thermistor: Four pieces
S. C.R: One piece
Supply voltage AC100V/117V/220V/240V, 50Hz/60Hz
Power consumption Maxima: 165VA (AC240V, 50Hz/60Hz)
Dimensions Width 435x height 155x depth of 334mm
Weight 12.3kg