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% good working condition and optically in very neat vintage condition with light signs of use consistent with its age.
For enthusiasts of classic Japanese industrial design and serious audio technology, the SU-3500 is an iconic model. The unit weighs just over 10 kilograms and is characterized by a solid, thick brushed aluminum front with beautifully machined knobs and sturdy toggle switches. Under the hood lies a fully discrete build with a hefty, shielded transformer and a directly coupled OCL output stage.
In terms of sound, this amplifier is known for its exceptionally stable, warm, and uncolored performance with a notably fast, tight bottom end and a very low noise floor. Particularly interesting for vinyl lovers is the double phono circuit: the SU-3500 features two phono inputs where input impedance and capacitance can be adjusted (impedance selector), allowing different cartridges to be matched exactly. Additionally, the tone controls offer adjustable turnover frequencies (turnover switches) and a dedicated defeat position to keep the signal path as pure as possible. Through the rear-panel pre-out/main-in connections, the preamp and power amp sections can also be used completely independently.
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)
Phono input capacitance and resistance: 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 (separable pre/power sections)
Speaker outputs: screw terminals for 2 speaker pairs (Main, Remote, Main+Remote)
Front panel connectors: 6.3 mm headphone jack
Power supply: 110–240 V AC selectable, 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)