SANSUI AU-777

Commentary

An all-silicon transistor pre-main amplifier created with the same design intent as the AU 111.

A C / E split phase inversion circuit is used for the output stage to realize an all-silicon transistor.
As a result, excellent high-frequency characteristics and linearity due to silicon transistors are obtained.

All amplifier circuits from the first stage to the final output stage are composed of NF amplifier, and frequency characteristics, distortion and SN are improved.

The tone control is a 2-stage NF type using a 3-dB-step attenuator.
In addition, the tone center provides a completely flat characteristic.

In order to prevent damage to the power transistor even if the output terminal is short-circuited, SANSUI's original pure electronic PSC (protection) circuit is adopted.
In addition, the AU 777 uses a double safety protection device that combines a power transistor with a quick fuse to ensure even greater safety.

The preamp section and power amplifier section can be used separately.
For this reason, it can be used as a multi-amplifier system by connecting a channel divider to the preamplifier jacks and adding a power amplifier.

It is equipped with two Phono input terminals, and Phono1 is designed for 47k Ω and Phono2 for 100k Ω.
Thus, it can be used depending on the load resistance of the cartridge.

Center channel output terminal is mounted, and 2 circuits of flat output and 200 Hz high-cut output are provided.

Equipped with a tape equalizer that can be switched according to the speed of the tape.

Equipped with CR feedback type low filter and high filter.

It is equipped with functions such as loudness control, tape monitor, presence switch, headphone jack and muting switch.

Model Rating

Solid-state pre-main amplifier
Power Amplifier Unit
Stereo effective output (both channel drive)	25W + 25W + / - 1 db
Effective power	30W/30W ± 1 db
Music power	70W + / - 1 db
Total harmonic distortion factor	Not more than 0.5%
Intermodulation distortion factor (60 hz : 7 khz = 4 : 1)	0.8%
Power Band With (IHF, 0.5% distortion factor)	20 Hz to 50 kHz
Frequency characteristic	20 Hz ~ 100 kHz ± 1 dB (Normal Output)
Channel separation	50dB
Hum and noise (IHF, closed circuit)	100dB
Input sensitivity (effective output, 1 kHz)	1V
Input impedance	300k Ω
Load impedance	8 Ω ~ 16 Ω
Damping factor	24 (8 Ω)
Center channel output	Flat Output : 9.5 V High Cut Output : 1 V (fo = 200 Hz)
Presence	50 Hz, + 6 dB (fo = 125 Hz)
Preamplifier Section
Output voltage	Maximum : 5 v Rating : 1 v (180 Ω)
Total harmonic distortion factor	0.1% (Rated Output Voltage)
Frequency characteristic	20 Hz ~ 70 kHz + 0.5 dB ~ -1.5 dB
Hum and noise (IHF)	Phono1, 2 : 80 dB (closed circuit) Tape Head 19cm/sec : 85 dB (closed circuit) AUX1, 2 : 85 dB (open circuit)
Input Sensitivity / Impedance (1 kHz)	Phono1 : 2mV/47k Ω Phono2 : 2mV/100k Ω Tape Head 19cm/sec : 1.5mV/200k Ω Tape Head 9.5cm/sec : 1.3mV/200k Ω AUX1, 2, Tape Monitor : 140mV/100k Ω
Tape Rec	Phono1, 2 : 37 dB (70 times the input) Tape Head 19cm/sec : 39 dB (90 times the input) Tape Head 9.5cm/sec : 41 dB (110 times the input)
Tone control	Bass : 20 Hz ± 15 dB (in 3 dB steps) Treble : 20 kHz ± 15 dB (in 3 dB steps)
Loudness control (Volume-30dB)	50 Hz : + 8 dB, 10 kHz : + 5 dB
High filter	20 kHz, -22dB
Low filter	20 Hz, -21dB
Muting	-20dB (20 Hz to 20 kHz)
Mode switch	Stereo (Norm, Rev) Mono (L, R)
<General>
Semiconductor used	Transistor : 26 Nos. Diode : 8 pcs Thermistor : 4 S. C. R : 1 Piece
Power supply voltage	AC100V/117V/220V/240V, 50Hz/60Hz
Power consumption	Maximum : 165 VA (240 VAC, 50Hz/60Hz)
External dimensions	Width 435x Height 155x Depth 334 mm
Weight	12.3kg
Sold Separately	Wooden case (¥ 4,150)