ขายแอมป์ SANSUI AU-7700 รุ่นใหญ่ท้ายเรือ เสียงดี สภาพสวย พร้อมใช้ Made in Japan
ขายแอมป์ SANSUI AU-7700 รุ่นใหญ่ท้ายเรือ เสียงดี สภาพสวย พร้อมใช้ Made in Japan
SANSUI AU-7700
¥99,800 (around 1975)
explanation
A pre-main amplifier that has been perfected by making full use of our experience and technology
in high-end components.
The structure of the panel on the back side is directly connected to the equalizer amplifier board
at the shortest distance, with the input terminals and the input terminals mounted upward,
including the Phono circuit.
As a result, there is no need to use shielded wires, which cause deterioration of high-frequency
characteristics, and the sound quality is achieved with a high signal-to-noise ratio and good
high-frequency characteristics.
It has an integrated structure in which the printed circuit board of the control amplifier, rotary
switches, lever switches, and various volumes are directly attached.
This prevents failures such as poor connections and improves reliability.
Along with the chassisless structure, one-point grounding is implemented to suppress current
mutual interference.
The power amplifier consists of a three-stage Darlington-connected drive stage with
a differential amplifier circuit in the first stage, and a parallel push-pull power stage.
The parallel push-pull method combines four power transistors with identical characteristics
per channel to achieve good linearity in current characteristics, and the pure complementary
circuit directly connected to all stages has excellent phase characteristics and is subjected to
large negative feedback over a wide bandwidth, resulting in flat frequency characteristics.
The equalizer circuit uses a four-stone equalizer circuit with a differential amplifier circuit at the
first stage input.
The carefully selected use of elements ensures an excellent dynamic range.
In addition to Bass and Treble, it is equipped with a triple tone control that can be adjusted for
Midrange. The configuration of the tone amplifier is a six-stone configuration with a differential
amplifier circuit in the first stage, and a low-noise type transistor,
Carefully selected high-precision CR elements are used, and a detent-type volume with low error
is adopted.
It is equipped with a tone selector switch that allows you to select the tone control Bass,
Treble descending, and rising frequency to 3 points.
A high filter is used that uses a dedicated NF type active filter with good characteristics.
Two types of damping characteristics can be selected, and at the deft position, the
characteristics become flat and independent of the filter circuit.
It is also equipped with a two-stage low filter.
Since the potential of the input/output circuit of each block stage is almost 0 V, the click noise
that occurs when the selector switch is switched is prevented.
When defetting, a complete deft method is used that bypasses the tone circuit and filter circuit.
At this deft, all stages ± operate with two power supplies.
The power supply section uses a heavy-duty power transformer and a large-capacity power
supply capacitor of 10,000 μFx2 to supply a ±2 power supply that is resistant to load fluctuations
such as large inputs and has good regulation.
In addition, the equalizer and tone circuits are supplied with power by a ±2 power supply
stabilization circuit with a power stage and a separate winding, thereby suppressing the influence
of the power stage.
It combines electronics with high-sensitivity relays, and also uses a fast-acting fuse to protect
the device.
The sensing circuits that operate most of the circuits are quadrupled: a temperature sensing
circuit for power transistors, a transistor safety area detection (ASO) circuit, an overcurrent
detection circuit, and an abnormal voltage detection circuit for speaker protection.
It is equipped with a two-stage loudness switch. It is possible to switch between the normal
low-high frequency boost and the low-frequency booth only.
The -15dB and -30dB attenuation also allows for fine adjustment of the music level.
It is equipped with a stereo normal/reverse/mono mode switching switch.
It is equipped with two tape monitor circuits, which can record the program source and monitor
it during recording.
It is also possible to make tape copies.
It is equipped with a pre-main disconnect switch, and the preamplifier and main amplifier parts
can be separated and used independently.
In the Phono input circuit, Phono1 is switched to three stages with a load impedance of 30 kΩ,
50 kΩ, and 100 kΩ, depending on the cartridge.
With the flip of a switch, two sets of speaker systems, A and B, can be played independently or
at the same time.
It is equipped with a large ground terminal and a spare AC outlet.
Die-cast side panels are used.
It uses a solid aluminum metal knob that feels good.
Model Ratings
Model Pre-main amplifier
Effective Output
Dual-channel operation 20Hz~20kHz:52W+52W(8Ω)
1kHz:55W+55W(8Ω)
Single-channel operation 1kHz:58W/58W(8Ω)
Music Power 250W(4Ω、1kHz)
Total Harmonic Distortion Pre Amp: 0.1% or
less Main Amp: 0.1% or
less Over All: 0.1% or less
Intermodulation distortion
(70Hz:7kHz=4:1, SMPTE) Pre Amp: 0.1% or
less Main Amp: 0.1% or
less Over All: 0.15% or less
Powerband Whiz (IHF) 5Hz~40kHz
Frequency response (at 1W output) 10Hz~50kHz +0.5 -1dB
RIAA Deviation (30Hz~15kHz) ±0.5dB
Damping Factor 30(8Ω)
Input sensitivity/impedance Phono1:2.5mV/30kΩ、50kΩ、100kΩ
Phono2:2.5mV/50kΩ
Tuner、AUX、Tape Monitor(Pin/Din):100mV/50kΩ
Main Amp:800mV/50kΩ
Phono Maximum Allowable Input (THD 0.2% or less) 300mV
Output voltage (1kHz) Tape Rec(Pin/Din):100mV/30mV
Pre Amp:800mV
Channel Separation (1kHz) Phono: 50dB or
more Tuner/AUX, Tape Monitor: 55dB or
more Main Amp: 60dB or more
Hum and Noise (IHF) Phono: 75dB or more
Tuner, AUX: 85dB or more
Main Amp: 100dB or more
Tone Control Bass:±13dB(50Hz)
Midrange:±5dB(1kHz)
Treble:±13dB(15kHz)
Tone Selector Bass:150Hz/300Hz/600Hz
Treble:2kHz/4kHz/8kHz
Loudness (Volume at -30dB) High & Low:+10dB(50Hz)、+8dB(10kHz)
Low:+10dB(50Hz)
Low filter 20Hz=-3dB(12dB/oct)
60Hz=-3dB(12dB/oct)
High Filter 7kHz=-3dB(6dB/oct)
12kHz=-3dB(12dB/oct)
Muting -15dB、-30dB
Rated power consumption 120W
External dimensions Width 434 x Height 130 x Depth 315 mm
weight 12.3kg