Beautiful example here. Just serviced. All controls cleaned and lubricated, New LED's, bias set, tuner dialed in, fully bench tested. Usual age related scuffs, scratches, dings. Looks and sounds wonderful! 

The Marantz Model 4240 is a vintage solid-state stereo and quadraphonic (4-channel) receiver produced by Marantz from 1974 to 1978.

Key Specifications & Performance

• Power Output: • 40 watts per channel into 8 ohms in 2-channel stereo mode • 17 watts per channel into 4 ohms (or 4x17W) in 4-channel quadraphonic mode

• Tuning Range: FM and AM (MW) with Gyro-Touch tuning • Frequency Response: 20 Hz to 20,000 Hz • Total Harmonic Distortion (THD): 0.5% (or ~0.15% depending on source standard) • Inputs & Outputs: Phono (Moving Magnet), Aux, Tape loops, 2 headphone jacks, and 4 speaker pairs • Dimensions & Weight: 440 x 137 x 365 mm; approximately 15.5 kg (34 lbs)

Core Features • Quadraphonic Capabilities: Features Marantz’s exclusive Vari-Matrix circuit, which simulates 4-channel sound from standard 2-channel stereo sources and plays back matrix-encoded or discrete 4-channel programs. • Optional Plug-In Decoders: Can accept optional plug-in modules like the SQA-1 or SQA-2 for Columbia SQ matrix decoding. • Classic Aesthetics: Brushed aluminum faceplate, iconic blue-illuminated dial, and dual-tuning/signal meters. • Dolby Circuitry: Includes internal circuitry for Dolby FM and Dolby noise reduction selectors.