Sansui AU-7500 (1972)

Solid State Integrated Amplifier

This professional stereo component, an integrated amplifier with unusually wide power bandwidth, says a lot about the way Japan's foremost audio only specialist meets the demanding requirements of the stereo world today. A perfect power match for the TU-7500 stereo tuner, the AU-7500 represents a significant milestone in Sansui's pursuit of excelence. Not only are these two products the most advanced of any 2-channel products ever made by Sansui, they also represent the pinnacle of the company's up-to-the-minute knowledge of audio acoustics and electronics.

The AU-7500 boasts such performance characteristics as total harmonic distortion and intermodulation distortion which has been limited to below 0,1% throughout the audio spectrum and well beyond. With its super-wide power bandwidth of 5 - 40,000 Hz, you can achieve RMS power of 43 watts into 8 ohms, along with total harmonic distortion of only 0,1%. Inside the AU-7500 are a PNP-NPN-PNP heterojunction three stage direct coupled equalizer amplifier with an input capacity of no less than 300 mV RMS resulting in such a wide dynamic range. There are also low noise PNP transistor tone control circuits and a direct coupled DCL pure complementary power amplifier employing two 6,800 μF jumbo power supply capacitors. Finally this professional amplifier is blessed with a variety of convenience features, including a 4-channel adaptor switch, the ability to connect up to three tape decks, and provisions for tape-to-tape dubbing. And in terms of tonal quality, the AU-7500 quite simply has no equal.

Specifications:

General

System: Transistor

Colour: Black, Silver frame

Power Output

IHF Music Power: 150 W (4 Ω, 1 kHz)

Continuous RMS Power: 43/43W (4 Ω, 1 kHz) each channel driven

Continuous RMS Power: 40 + 40 W (8 Ω,1 kHz) both channel driven

Continuous RMS Power: 32 +32 W at 8 Ω (both channel driven at rated distortion, 20 to 20,000 Hz)

Total Harmonic Distortion: less than 0,1% at rated power

Intermodulation Distortion: less than 0,1% at rated output (70 Hz:7,000Hz=4:1 SMPTE method)

IHF Power Bandwidth: 5 to 40,000 Hz (each channel driven at 8 Ω)

Frequency Response (at 1 watt power output):

Phono 1, 2: ±0,5 dB (30 - 15,000 Hz) RIAA

Over-all (from Aux): 10 - 30,000 Hz; ±1 dB

Main Input: 10 - 50,000 Hz; ±1 dB

load Impedance: 4 to 16 Ω

Damping Factor: approx 40 at 8 Ω load

Pre Amplifier

Inputs: Phono MM I, Phono MM II, Mic, Tuner, Tape, Monitor

Input Sensitivity/Impedance at 1 kHz:

Phono 1: 2,5 mV/50 kΩ

Phono 2: 2,5 mV/30, 50, 100 kΩ

Max. Input Capability: 300 mV (THD, less than 0,5%)

Microphone: 2,5 mV/50 kΩ

Tuner, Aux: 100 mV/50 kΩ

Tape 1, 2: 100 mV/50 kΩ (Pin, DIN)

4-ch Adapter: 100 mV/50 kΩ

Main Input: 800 mV/40 kΩ

Output Voltage at 1 kHz:

Phono 1, 2: better than 50 dB

Mic, Tuner, Aux: better than 50 dB

Main Input: better than 65 dB

IHF Hun and Noise:

Phono 1, 2: better than 75 dB

Microphone: better than 75 dB

Tuner, Aux: better than 80 dB

Main input: better than 100 dB

Tone Controls:

Bass : ±15 dB at 50 Hz,

Midrange: ±5 dB at 1,500 Hz

Treble: ±15 dB at 15 kHz

Loudness: +10 dB at 50 Hz; +10 dB at 15 kHz (volume control at -30 dB)

Low Filter: -12 dB at 50 Hz (12 dB/oct)

High Filter: -11 dB at 10 kHz (12 dB/oct)

Power Amplifier

Speaker Outputs: 1 x 2 Speakers, Phones

Continuous power 8Ω: 2 x 40 Watts

Dynamic Power 4Ω: 2 x 75 Watts

Frequency Response: 5 - 40,000 Hz

Harmonic Distortion: 0.1 % at rated output

Semiconductors: 38 transistors; 15 diodes; 1 zener diode

Power Requirements: 100 -250 V, 50/60 Hz

Power Consumption: 315 VA (maximum); 100 W (rated)

Physical

Dimensions (W x H x D): 440 x 140 x 322 mm (17-3/8 x 5-9/16 x 12-11/16 inch)

Weight: 12.7 Kg (28 lbs)