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Marantz 4140 Stereo 2 / 4-Channel Integrated Amplifier – Wood Case IncludedProfessionally Restored by HQaudios - Inspected & Tested - Backed by Our 1-Year Warranty1. KEY HIGHLIGHTSMarantz 4140 stereo 2 / quadraphonic 4-channel integrated amplifier70 W x 2 in stereo mode or 25 W x 4 in 4-channel modeFour illuminated VU power metersVari-Matrix quadraphonic circuit with provision for an optional SQ decoder moduleIndependent front and rear bass / mid / treble controlsWood case shown in the photos includedProfessionally restored and tested by HQaudiosBacked by our 1-Year HQaudios Warranty2. PRODUCT OVERVIEWThe Marantz 4140 is a mid-1970s stereo 2 / 4-channel integrated amplifier, produced from 1975 to 1978, built to run either as a high-power stereo amplifier or as the heart of a quadraphonic system.It delivers 70 W x 2 in stereo operation or 25 W x 4 in 4-channel operation, with four illuminated VU power meters, Marantz Vari-Matrix circuitry and independent front and rear bass, midrange and treble controls.We restored this unit with careful attention to technical operation and cosmetic presentation, while preserving the original Marantz design and character.3. HQAUDIOS RESTORATION & TESTINGBefore RestorationWhen we received this Marantz 4140, we performed a complete visual, electrical, and functional inspection before beginning the restoration process.The inspection covered the power supply, amplifier stages, phono and preamplifier sections, controls, switches, meters and lamp illumination, and was used to determine the service needed for this specific unit.During RestorationWe restored this Marantz 4140 according to our HQaudios restoration standards while preserving the original Marantz design and components.Amplifier & Power Supply: We inspected and serviced the amplifier circuitry and power supply, replacing selected aging electronic components as documented in our completed service records.Controls & Switches: The volume control, tone controls, sliders and push-button switches were cleaned.Meter Illumination: The VU meter illumination was serviced.Cleaning & Detailing: The chassis, faceplate, controls and wood case were cleaned and detailed.After Restoration / Final TestingAfter the restoration was completed, the unit underwent final functional and listening tests.Amplifier Output: All channels were checked for proper, consistent output in stereo and 4-channel modes.Quadraphonic Functions: Vari-Matrix and 4-channel operation were checked.Tone & Balance Controls: Front and rear bass, mid, treble and balance controls were checked for smooth, noise-free adjustment.Inputs & Meters: Phono, tuner, aux and tape inputs and the VU meters were checked.Listening Test: The amplifier was evaluated using real music playback over an extended session.Final QC: A complete visual and functional quality-control inspection was completed before release.4. CONDITIONTechnical ConditionAmplifier & Power Supply: ServicedControls & Switches: Cleaned and operatingVU Meters: Illumination serviced, meters respondingOperating Modes: Stereo and 4-channel modes checkedPower: AC 120VCosmetic ConditionFaceplate: Brushed aluminum faceplate with legible original markingsKnobs & Sliders: Original controls presentVU Meters: Four illuminated meters presentWood Case: Included, as shown in the photosRear Panel: Original speaker terminals, RCA connections and rear-panel controlsOverall Presentation: A vintage amplifier with normal signs of age and previous use. Please review all photos for exact cosmetic details.Summary:Amplifier ServicedAll Channels TestedFinal Listening Test Completed5. SPECIFICATIONSBrand: MarantzModel: 4140Type: Stereo 2 / 4-Channel Integrated AmplifierYears: 1975 - 1978Power Output: 70 W x 2 (stereo) / 25 W x 4 (4-channel), 8 ohms, 20 Hz - 20 kHzTotal Harmonic Distortion: 0.3%Intermodulation Distortion: 0.3%Frequency Response: 20 Hz - 20 kHz, ±1.0 dB (at 1 W)High-Level Input: 150 mV / 100k ohmsDamping Factor: 40Quadraphonic System: Vari-Matrix; provision for optional SQ decoder modulePower: AC 120V6. WHAT IS INCLUDED1 Marantz 4140 Integrated AmplifierWood case shown in the listing photosAttached AC power cordOnly the items specifically listed above are included. Speakers, cables, remote control and other accessories are not included.7. SHIPPING & PACKAGINGYour vintage audio equipment will be professionally packed by HQaudios using protective materials appropriate for its size, weight, and construction. Large or heavy items may be palletized and shipped by freight when required for safer transportation.Please contact us before purchase for the most current availability information.8. 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, operation, compatibility, or your order, please contact HQaudios for assistance.
Age matters here: this is a 1970s quadraphonic-era Marantz, not a current AV receiver, so originality and service history matter more than the model name alone. At US$2,999, the asking price is ambitious against the available comparables: the median is US$2,199, with the 75th percentile at US$2,599. It would need exceptional restoration, cosmetics, and documentation to justify the premium.
The 4140 is a desirable, substantial vintage unit that can deliver a warm, powerful stereo presentation while retaining its unusual four-channel capability. Its rarity, distinctive design, and appeal to collectors are genuine strengths, but US$2,999 should buy a properly serviced example with reliable controls, clean output across all channels, and ideally proof of restoration. For an unrestored or merely tested unit, this is a pass or negotiation candidate rather than a bargain.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.
Marantz originated in the United States, founded in 1953 by Saul Bernard Marantz, a music enthusiast and amateur musician born in Brooklyn in 1911. Dissatisfied with the audio equipment of the era, he crafted the groundbreaking Audio Consolette preamplifier in 1952 from his New York home, selling the first 100 units rapidly and prompting the formal establishment of the company in Woodside, Queens. Though production later shifted to Japan in partnership with manufacturers like Standard Radio in 1966, and the brand evolved through ownership changes including Superscope and eventual integration into larger groups, its heritage remains rooted in American ingenuity and a relentless pursuit of musical fidelity.
The brand excels in high-end audio components, particularly amplifiers, preamplifiers, and integrated systems that defined its golden era. Iconic models like the Model 7 preamplifier (1958), Model 9 power amplifier (1960), and Model 10B tuner (1964) set benchmarks for performance, while later offerings expanded to tuners, receivers, and CD players. Marantz briefly ventured into speakers under designer Ed May in the 1970s but focused primarily on electronics rather than turntables, headphones, DACs, or cables, emphasizing separates renowned for their "Most Musical Sound."
Marantz commands a premium position in the hi-fi market, revered as a high-end pioneer that shaped the audiophile landscape through the 1970s zenith. Today, it blends vintage allure with modern elegance, appealing to discerning buyers who value durability, innovation, and warm, detailed sound signatures over mass-market accessibility.
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