Garden Grove, CA, United States
About this listing
Marantz 4270 - Custom Black - Free WC-22 Wood Case - Restored - 1-Year WarrantyCustom Black Faceplate - Wood Case Included - Professionally Serviced by HQaudios1/ KEY HIGHLIGHTSMarantz 4270 Stereo 2 + Quadradial 4 AM/FM receiver70 W x 2 Stereo / 25 W x 4 Quadraphonic OperationBridge-configured stereo amplification with dedicated front speaker outputsCustom black faceplate with gold-colored lettering and silver controlsWood case included, as shown in the actual product photographsBuilt-in Vari-Matrix four-channel synthesisBuilt-in Dolby noise-reduction circuitry and Dolby FM capabilityClassic Gyro-Touch tuning with blue-illuminated dialDedicated bass, midrange and treble tone controlsRear-panel Power Mode switch for stereo and quadraphonic configurationsSeparate FRONT and REAR PRE OUT / MAIN IN connections120V AC, 50/60Hz - U.S. mains compatibleCustom exterior presentation and technical servicing by HQaudiosBacked by our 1-Year HQaudios Warranty2/ PRODUCT OVERVIEWThe Marantz 4270 is a classic mid-1970s receiver from Marantz's celebrated quadraphonic era, combining traditional two-channel stereo reproduction with the flexibility of four-channel listening.Its distinctive Stereo 2 + Quadradial 4 architecture provides two operating configurations: 70 watts per channel in bridged stereo mode or 25 watts per channel across four channels in quadraphonic mode, into 8-ohm loads.In the high-power stereo configuration, the amplifier stages operate in a bridged arrangement, delivering output through the FRONT speaker terminals. Quadraphonic mode provides separate front and rear channel amplification for a four-speaker system.The receiver features Marantz's renowned Gyro-Touch tuning, a traditional blue-illuminated analog dial, signal and tuning meters, comprehensive tone controls, built-in Dolby circuitry and Vari-Matrix processing.Vari-Matrix allows synthesized four-channel reproduction from suitable stereo sources, making the 4270 especially appealing to enthusiasts exploring vintage multichannel audio. The dedicated SQ decoding system was a separate optional configuration.This particular receiver stands out with a custom black faceplate, gold-colored control lettering, contrasting silver knobs and a matching wood case. The black front-panel treatment is a custom finish rather than a claim of a factory-original black edition.Our HQaudios team has carried out technical evaluation, servicing and cosmetic detailing while maintaining the receiver's distinctive Marantz design and vintage character.3/ HQAUDIOS RESTORATION & TESTINGBefore RestorationWhen this Marantz 4270 entered our workshop, our technicians evaluated its overall electrical, mechanical and cosmetic condition.The inspection covered the power-supply and amplifier sections, signal connections, front-panel controls, tuning system, dial illumination and accessible internal assemblies.Particular attention was given to aging electrolytic components in the electronic circuitry, the operating condition of the controls and switches, and the condition of the receiver's external fittings.The faceplate, dial window, silver controls and wooden case were also examined for age-related wear before exterior detailing.During RestorationOur HQaudios technicians carried out service and exterior detailing while preserving the Marantz 4270's Stereo 2 + Quadradial 4 operating architecture.Electronic Circuit Inspection: The amplifier and power-supply circuitry was examined, including electrolytic capacitor positions requiring attention due to age and operating condition.Controls & Switches: The volume, tone, balance, slider and push-button control assemblies were inspected and serviced as part of the operating evaluation.Dial & Meter Assemblies: The illuminated tuning display and meter assemblies received inspection and servicing attention while maintaining the classic Marantz presentation.Power Mode System: The stereo and quadraphonic power-mode configuration and corresponding rear-panel connections were reviewed during technical service.Signal Connections: The FRONT and REAR PRE OUT / MAIN IN connection areas were examined as part of the receiver's operating configuration.Custom Faceplate & Exterior: The custom black faceplate, silver controls, chassis surfaces and wooden case were cleaned and detailed for an improved overall vintage presentation.Final Preparation: The receiver was assembled and prepared for subsequent functional and listening evaluation.After Restoration / Final TestingFollowing service, the receiver was evaluated for stereo audio reproduction and general operating condition.Stereo Audio Playback: The receiver was evaluated with a stereo audio signal, with left and right output operation assessed during listening.Front-Channel Operation: The front amplifier outputs were included in the stereo playback evaluation.Controls & Signal Routing: The receiver's front-panel adjustments and source-selection functions were reviewed for normal operating response.Dial & Tuning Display: The illuminated analog display and tuning-meter presentation were included in the post-service functional evaluation.Listening Evaluation: The receiver was assessed during music playback for stereo output and overall audible performance.Operating Configuration: The 4270 retains its selectable 70W x 2 stereo and 25W x 4 quadraphonic architecture. Correct PRE OUT / MAIN IN connections are required for normal use of the respective amplifier sections.4/ CONDITIONTechnical ConditionStereo Amplifier: The receiver underwent technical servicing and stereo playback evaluation. Left and right front-channel audio operation was assessed through music reproduction following service.Quadraphonic Amplifier Configuration: The original four-channel amplifier architecture remains present, together with the rear-panel Power Mode selector and separate front/rear signal connections. The rear PRE OUT / MAIN IN connections require their corresponding links for normal four-channel operation.Power Supply & Electronic Assemblies: The amplifier and power-supply sections received technical inspection, including attention to aging electrolytic components. Stereo playback evaluation was carried out following service.Volume & Tone Controls: The rotary and slider control assemblies were included in the service process and operating evaluation. Their response was assessed as part of the receiver's stereo playback functions.Tuning System: The Gyro-Touch tuning mechanism, analog dial and meter assemblies were inspected as part of the receiver's operating evaluation.Dolby & Vari-Matrix: The receiver retains its built-in Dolby and Vari-Matrix circuitry and associated user controls. Vari-Matrix provides the receiver's original synthesized four-channel capability.PRE OUT / MAIN IN Connections: Separate front and rear signal-loop connections remain present on the rear panel. Proper jumper connections, or appropriate external signal routing, are required for normal amplifier operation.AC Power: The receiver is factory-rated for 120V AC, 50/60Hz operation, suitable for standard U.S. mains power.Cosmetic ConditionCustom Black Faceplate: The receiver features a distinctive black front-panel finish with gold-colored lettering and contrasting silver controls. The custom treatment is separate from the factory-original standard faceplate appearance.Dial Glass: The large tuning display retains its classic Marantz appearance with blue illumination. Fine scratches and minor age-related marks remain visible on portions of the dial-window surface.Signal & Tuning Meters: The front-panel analog meter assemblies are present behind the display window, maintaining the characteristic Marantz receiver layout.Knobs & Controls: Silver rotary knobs, slider controls and push-button switches are present. Minor signs of vintage use may be visible around frequently handled surfaces.Wood Case: The receiver includes the fitted wood case shown in the actual photographs. The warm wood-grain finish presents attractively overall, with minor scratches, edge wear and age-related finish variations remaining.Upper & Side Surfaces: The case panels retain their wood-grain appearance, with small variations in surface finish and minor marks from previous use.Rear Panel: The rear panel retains the original-style speaker-terminal groups, FRONT and REAR PRE OUT / MAIN IN connections, antenna connections, voltage identification and power-mode selection layout.Rear Labels & Markings: The receiver's connection labels and AC 120V identification remain visible. Normal wear to rear hardware and markings may be present.Overall Appearance: A distinctive custom-finished vintage Marantz 4270 with black-and-silver front styling and included wood case. Minor scratches and age-related marks remain, particularly around the dial glass and wooden case surfaces. Please review the actual photographs for the exact cosmetic condition.Stereo Playback CheckedFront-Channel Audio Operation EvaluatedExterior Detailing Completed5/ IMPORTANT OPERATING NOTESStereo Mode - 70W x 2: The receiver operates in a bridged-amplifier configuration. Connect speakers to the FRONT speaker terminals only. Use speakers rated at 8 ohms or higher.Quadraphonic Mode - 25W x 4: The receiver provides separate front and rear amplifier channels for four-speaker operation when correctly configured.Power Mode Selection: Always turn the receiver OFF before changing the rear-panel POWER MODE switch. Never change amplifier mode while the unit is powered on.Bridged Stereo Speaker Connections: The speaker outputs are not common-ground in 70W x 2 mode. Do not use speaker selectors, test devices or accessories that connect speaker negative terminals together.PRE OUT / MAIN IN Connections: For normal internal operation, the corresponding PRE OUT and MAIN IN jacks must be connected with the correct jumper links. These connections must be properly configured before operating the associated amplifier channels.Rear-Channel Connections: The rear PRE OUT / MAIN IN links are not shown installed in the available rear-panel photograph. Their presence and correct configuration should be confirmed before four-channel use.Vari-Matrix & SQ: The built-in Vari-Matrix circuitry allows synthesized four-channel playback from suitable stereo material. This description does not indicate that an optional dedicated SQ decoder module is installed.6/ FACTORY TECHNICAL SPECIFICATIONSBrand: MarantzModel: 4270Type: Stereo 2 + Quadradial 4 AM/FM ReceiverEra: Mid-1970sCountry of Manufacture: JapanStereo Power Output: 70 Watts x 2 into 8 OhmsQuadraphonic Power Output: 25 Watts x 4 into 8 OhmsStereo Amplifier Configuration: BTL / Bridged StereoStereo Mode Speaker Outputs: FRONT Terminals OnlyStereo Mode THD: 0.3%Damping Factor: 45Frequency Response: 20 Hz - 20 kHz (±1 dB at 1W output)Phono Input Sensitivity: 2.2 mV / 47 kOhmsLine Input Sensitivity: 150 mV / 100 kOhmsAudio Inputs: Phono, AUX, Tape 1, Tape 2, Four-Channel InputsSignal Connections: FRONT and REAR PRE OUT / MAIN INTone Controls: Bass, Midrange, TrebleBass Control: +/-10 dB at 50 HzMidrange Control: +/-10 dB at 700 HzTreble Control: +/-10 dB at 15 kHzBuilt-In Processing: Dolby Noise Reduction / Vari-MatrixTuning: Gyro-Touch Analog AM/FMFM Sensitivity: 2.2 microvoltsAC Power Requirement: 120V AC / 50-60HzPower Consumption: 400 Watts (Rear-Panel Rating)Factory Chassis Dimensions: Approximately 17.33 W x 5.39 H x 14.38 D inchesFactory Chassis Weight: Approximately 40.2 lbs / 18.2 kg, excluding additional wood-case and shipping materialsActual Front Finish: Custom Black Faceplate / Gold-Colored Lettering / Silver ControlsWood Case: Included, as shown in actual photographs7/ WHAT IS INCLUDED1 Marantz 4270 Stereo / Quadraphonic Receiver with custom black faceplate1 Wood Case fitted to the receiver, as shown in the listing photographsAttached AC Power CordOnly the items specifically listed above are included. Speakers, separate audio cables, external processors, optional decoder modules and other display accessories are not included unless expressly stated.8/ SHIPPING & PACKAGINGThe Marantz 4270 is a substantial vintage receiver weighing approximately 40.2 lbs / 18.2 kg before accounting for its additional wood case and shipping materials.HQaudios will professionally protect and pack this receiver using appropriate cushioning, reinforced packaging and special care for its delicate vintage components.Front-Panel Protection: The custom black faceplate, dial glass, tuning window, knobs, switches and sliders will receive protective cushioning against direct pressure.Wood-Case Protection: The case surfaces, edges and corners will be protected to reduce the risk of scratches, abrasions and handling damage.Secure Internal Positioning: The receiver will be cushioned to limit movement inside the shipping carton during transit.Reinforced Boxing: Appropriate outer-carton reinforcement, impact protection and double boxing will be used when needed for safer transportation.9/ 1-YEAR WARRANTY & CUSTOMER SUPPORTYour purchase is backed by our 1-Year HQaudios Warranty. Our team provides support before and after your purchase. If you have questions about setup, correct Stereo/Quad mode selection, speaker connections, compatibility or your order, please contact HQaudios for assistance.MORE FROM HQAUDIOS
Price$2,999
Free Shipping
Free Shipping
from Garden Grove, CA
30-Day Return Policy
Enjoy peace of mind with your new gear
