Your Marantz Model 4270 is a high-quality Stereo 2 + Quadradial 4 Receiver developed by Marantz, a name famous for quality in the audio component industry. The Model 4270 incorporates Marantz' exclusive Vari-Matrix circuit which simulates 4-channel sound from normal 2-channel stereo programs, and is capable of reproducing 4-channel sound from any matrix-encoded source. The 4270 will also reproduce any discrete 4- channel program as well as regular stereo and monaural programs. An optional plug-in decoder adapts the 4270 for any specific matrix system such as Columbia's SQ. The FM tuner section employs an FET for the RF amp and Mixer stage. The IF tuning circuit employs ceramic filters of wide bandwidth and high selectivity to provide high sensitivity and unparalleled interference-free operation. The 4270 incorporates a switchable 2-channel DOLBY system to reduce noise, inherent in recording music from records, tape, FM broadcasts and TV. The FM multiplex circuitry includes a phase locked loop Stereo-Monaural Automatic switching circuit, stereo indicator circuit and a buffer amplifier to obtain output at low impedance. Low pass filters for 19KHz and 3SKHz rejection are incorporated. Moreover, the Model 4270 unit has a muting circuit that permits pleasant FM broadcast reception by completely eliminating inter-station interference which is usually generated at the time of selecting FM stations. TECHNICAL SPECIFICATIONS FM SECTION: Tuning Frequency Range............................................................................................... 88 — 108 MHz IHFM Usable Sensitivity..............................................................................................................23μ/ I HF Selectivity...............................................................................................................................60 dB Capture Ratio...............................................................................................................................1.6 dB Image Rejection Ratio at 106 MHz............................................................................................70 dB Signal to Noise Ratio (Mono) .....................................................................................................70 dB Signal to Noise Ratio (Stereo) ...................................................................................................60 dB Total Harmonic Distortion (Mono)...............................................................................................0.2% Total Harmonic Distortion (Stereo)...............................................................................................0.3% Frequency Response (ref. 75μ sec. de-emphasis)........................................30 Hz to 15 KHz, ± 1 dB Stereo Separationat 1 KHz..........................................................................................................40 dB Quadradial Output (400 Hz 75 KHz dev.)...............................................................................300mV AM SECTION: Tuning Frequency Range.......................................................................................... 540 — 1605 KHz Usable Sensitivity ......................................................................................................................... 30μν Selectivity.....................................................................................................................................26 dB Image Rejection Ratio at 1400 KHz..........................................................................................70 dB Signal to Noise Ratio ..................................................................................................................45 dB Frequency Response (—6 dB) .................................................................................50 Hz to 3.5 KHz Total Harmonic Distortion ................................................................................................................1% AUDIO SECTION: Input Impedance — Low level input......................................................................Phono 47K ohms — High level input.................................................................................100K ohms I nput Sensitivity — Phono.............................................................................2.2mV for 25W output — High level.........................................................................150mV for 25W output Frequency Response ...........................................................................+1.0 dB, 20 Hz to 20 KHz at 1W output Intermodulation Distortion........................................................................... Less than 0.3% at rated power output Total Harmonic Distortion .............................................................................Less than 0.3% at rated power output Damping Factor ............................................................................................More than 45 at 8 ohms Total Noise — From magnetic phono input............................................Less than 2μ/ equivalent to power amp output input noise at 8 ohms rated power output Volume Tracking........................................................................................................... Less than 4 dB Rated Continuous (RMS) Output...............................................................................25Wat8ohms all channels operating simultaneously at 40 Hz to 25W at 4 ohms 20 KHz for nominal harmonic distortion 13W at 16 ohms Comparable Total Music Power.................................................................................150W at 8 ohms GENERAL: Power Requirements 120 V Power Consumption — at rated power output, all channels.................................................. 400W — idling (no signal).................................................................................45W Dimensions — Panel Width...................................................................................17-21/64 Inches — Panel Height................................................................................... 5-25/64 Inches — Depth ................................................................................................14-3/8 Inches — Width (Packed for Shipment)............................................................22-1/4 Inches — Height (Packed for Shipment)..........................................................10-1/2 Inches — Depth (Packed for Shipment)..........................................................19-1/2 Inches Weight — Unit alone..........................................................................................................40.2 lbs — Packed for Shipment.......................................................................................... 49.1 lbs