Technics - SU-3500 Solid state integrated amplifier

Technics SU-3500 integrated stereo amplifier from the absolute top tier of Matsushita's early golden years (circa 1975–1977). Technically in 100% fully functional condition and visually in very tidy vintage condition with light signs of use consistent with the age.
For enthusiasts of classic Japanese industrial design and serious audio technology, the SU-3500 is an iconic model. The unit weighs over 10 kilograms and is characterized by a solid, thick brushed aluminum front with beautifully milled knobs and robust toggle switches. Under the hood lies a fully discrete construction with a substantial, shielded transformer and a directly coupled OCL output stage.
In terms of sound, this amplifier is known for its extremely stable, warm and uncolored reproduction with notably fast, tight bass and a very low noise floor. Particularly interesting for vinyl lovers is the dual phono circuit: the SU-3500 features two phono inputs with adjustable input resistance and capacitance (impedance selector), allowing exact matching of different cartridges. Additionally, the tone control offers adjustable turnover frequencies (turnover switches) and a dedicated defeat mode to keep the signal path as pure as possible. Via the rear pre-out/main-in connections, the preamp and power amp sections can also be used entirely separately.
Specifications
Type: integrated stereo hi-fi amplifier
Model: Technics SU-3500
Year of manufacture: circa 1975–1977
Continuous output power: 2 x 41 Watts RMS into 8 Ohms (2 x 43 Watts into 4 Ohms) with both channels continuously rated
Frequency response: 5 Hz – 100,000 Hz (+0 / -3 dB, Main In), 20 Hz – 20,000 Hz (Phono RIAA ±0.3 dB)
Total Harmonic Distortion (THD): 0.08% at nominal power
Intermodulation Distortion (IMD): 0.08%
Damping factor: 50 (8 Ohms)
Signal-to-noise ratio: 70 dB (Phono), 90 dB (Line/Tuner/Aux)
Input capacitance and resistance Phono: Phono 1 (47 kOhm), Phono 2 (adjustable: 25 kOhm, 60 kOhm, 100 kOhm)
Tone controls: Bass (±10 dB at 50 Hz, turnover: 250 Hz / 500 Hz), Treble (±10 dB at 20 kHz, turnover: 2.5 kHz / 5 kHz), with Tone Defeat
Filters: Low Filter (Subsonic 15 Hz / 30 Hz), High Filter (7 kHz / 14 kHz)
Inputs: Phono 1 (MM), Phono 2 (MM), Tuner, Aux 1, Aux 2, Tape 1 (RCA & DIN), Tape 2 (RCA)
Outputs: Tape Rec Out 1 & 2, Pre-Out, Main-In (separate pre/power sections)
Speaker outputs: screw terminals for 2 speaker pairs (Main, Remote, Main+Remote)
Front panel connections: 6.3 mm headphone jack
Power supply: 110–240 V AC switchable, 50/60 Hz
Power consumption: 330 Watts maximum
Dimensions (W x H x D): 41.0 x 14.0 x 34.0 cm
Weight: 10.2 kg
Manufacturer: Matsushita Electric Industrial Co., Ltd. (Osaka, Japan)