McIntosh MR77 Vintage FM Tuner - Modafferi Serviced

Description: McIntosh MR77 Vintage FM Tuner - Modafferi Serviced SkyFi Audio - Curators of Vintage Audio GearSkyFi Audio is a small startup business specializing in the purchase, reconditioning, and reselling of high end audio equipment. We only buy equipment that we admire and are passionate about. No mid-fi, no gimmicks, no junk. Each piece of equipment is cosmetically restored and fully tested in our well-equipped lab by an engineer with 30+ years of experience in the HiFi world. If it does not meet or exceed the original manufactures specifications, it will not be sold. We are very selective about the equipment we purchase, focusing on mostly analog, high-build quality, American, and European built units.Through our sister company, which is an authorized dealer for McIntosh, Audio Research, Sonus Faber, ClearAudio, Project, and Sony ES, we have access to OEM parts, service, and support.---------- If you haven't heard a vintage FM tuner recently, you really owe it to yourself to give one a listen. The right model matched with the proper antenna will make some of the warmest and most natural sounding music you've (ever) heard. Especially through an all analog piece like this McIntosh MR77. Plus this example shows signs of being serviced by the legendary FM guru Mr. Richard Modafferi in 1990! We are very lucky in our area to have some of the best sounding stations in the world, and you better believe we take full advantage. If you come to our shop you're likely to hear our local Jazz station WBGO playing from one of our vintage tuners just like this one. Sitting just below the renowned McIntosh MR78, this MR77 model provides 99% of the sound quality with a just a few removed features, which most users would never ever use or miss. My favorite feature (that's actually not found in the MR78!) is the "magic eye" indicator. It's an actual tube-based light emitting component with two lines that fluctuate indicating multipath reception. Super cool! Condition is very good with only the slightest signs of use. The cabinet is very presentable for its age and looks amazing when matched with this tuner. Thoroughly tested in our lab utilizing our Sencore SG80 FM Generator, which allows us to generate a reference FM signal of any frequency and amplitude, and then measure the results of the MR77 tuner output on our Sencore PR81 or oscilloscope. This unit passed with flying colors and produced a natural and warm sounding output. SkyFi Service Notes:• Unit shows signs of being serviced by the legendary FM guru Mr. Richard Modafferi in 1990. • Unit arrived still working well and needed only slight tweaking and a single tube replaced after testing in our Amplitrex. SkyFi Cosmetic Notes:• Very clean considering its age at 50+ years, and with no rust. • Glass has a few defects and there are a few scratches on the top edge (See Photos). Technical Specifications: SENSITIVITY: 2μV for 35 dB of quieting; 2.5μA at 100% modulation (±75 kHz deviation) for 3% total noise and harmonic distortionSIGNAL TO NOISE RATIO: 75 dB below 100% modulationHARMONIC DISTORTION:0.2% mono or stereo at 100% modulation, 20 Hz to 15,000 Hz. Typically, 0.05% at 1,000HzDRIFT: 25,000 Hz in first two minutes; thereafter 5,000 Hz at 25°C in 24 hoursFREQUENCY RESPONSE:±1 dB 20 Hz to 15,000 Hz with standard de-emphasis, (75μS) and 19,000 Hz pilot filterCAPTURE RATIO: 0.25 dB detector only; 2.5 dB complete tunerSELECTIVITY: Adjacent channel 6 dB IHF, carrier 47 dB down; Alternate channel 50 dB IHF, carrier 90 dB downSPURIOUS REJECTION: 100 dB IHFIMAGE REJECTION: 100 dB; 88 to 108 MHz (IHF)MAXIMUM SIGNAL INPUT: 12 volts across 300 ohms antenna terminals will not increase harmonic or intermodulation distortionINTERMODULATION DISTORTION: 0.2% mono or stereo for any combination of frequencies from 20 Hz to 15,000 Hz with peak modulation equal to 100% or less. Typically 0.1%AUDIO HUM: 75 dB down from 100% modulationMUTING: 70 dB noise reduction between stationsMUTING THRESHOLD: Position 1; 5 μ V ; Position 2, 20μVSCA FILTER:50 dB down from 67 kHz to 74 kHz; 275 dB per octave slopeSTEREO SEPARATION:40 dB at 1,000 HzSTEREO FILTER:10 dB noise reduction in position 120 dB noise reduction in position 2ANTENNA INPUTS:300 ohms balanced; 75 ohms un- balancedAUDIO OUTPUT:2.5 volts into 47,000 ohms; 1 volt into 600 ohms from fixed outputPOWER REQUIREMENT:120 volts, 50/60 Hz. 35 wattsIF SYSTEM:8-Pole Rimo Filter, 2 IC's, 1 J-Fet, and push-pull overlay power transistor stage driving a linear phase bridge discriminatorSTEREO INDICATOR:Front panel stereo light activated by 19,000 Hz onlyAUTOMATIC MONO-STEREO SWITCH:Mclntosh developed; all electronic automatic mono-stereo switching circuitSEMICONDUCTOR COMPLEMENT: 21 Transistors, 24 Diodes, 4 Integrated Circuits, 1 Indicator TubeSIZE:Front panel measures 16 inches wide (40.64 cm) by 5-7/16 inches high (13.81 cm). Chassis measures 15 inches wide (38.1 cm) by 13 inches deep (33.02 cm), including PANLOC shelf and back panel connectors. Knob clearance required is 11⁄2 inches (3.81 cm) in front of mounting panelFINISH:Front panel is anodized gold and black with special Mclntosh gold/teal panel nomenclature illumination. Chassis is chrome and blackMOUNTING:Exclusive Mclntosh developed professional PANLOCWEIGHT:27 pounds (12.25 kg) net, 39 pounds (17.69 kg) in shipping carton The SkyFi Testing Process for Tuners: We start with a visual inspection of all internal components to make sure that there are no signs of heat stress or damage. Capacitors are checked for telltale signs of predictive failure including bulging, shrunken wrappers, or physical leakage. We also inspect the PCBs for discoloration from resistors or transistors that may have been running hot. On vintage units we often spot check select capacitors for value and ESR. Vintage analog tuners also have moving parts related to the tuning gang and dial string. These parts are inspected for smooth operation. If the unit passes visual inspection it is bench tested for a handful of key performance parameters using a Sencore SG80 AM/FM Stereo Analyzer. The SG80 allows us to “simulate” an ideal radio station using precision test signals instead of music. This device, in conjunction with an oscilloscope allows us to properly evaluate the following parameters: 1. AM Reception (Where Applicable) 2. FM Mono Reception & Tuning Meter Function 3. FM MPX Reception (Stereo) 4. Dial Tracking - How accurately the tuner dial or display indicates the actual frequency of the broadcast being received. 5. Stereo Separation - A properly working stereo tuner will have minimal crosstalk between the left and right channel. 6. Sensitivity & Signal Strength Meter Function - By lowering the output of the SG80 we can simulate weak stations and determine how well the tuner will be able to pull in weak distant stations. This adjustment also helps us verify signal strength meter function. If the tuner has acceptable performance related to the parameters above we connect the unit for listening tests with a simple dipole antenna. We listen for audio reproduction quality of local stations and evaluate how many stations the tuner can receive while we sweep through the dial. We are looking to verify that the tuner can decode stereo on strong local broadcasts and pick up a wide variety of local stations at the bottom, middle, and top of the frequency band. At this point we also test convenience features such as muting, filters, built in oscilloscope function, etc. We finish up with an extended listening test on our long term test rig. We tune in a strong local station and monitor for drift over a 2-3 hour period. Item Included Original Box Not Included Manual Not Included Remote Not Applicable Cables Yes - Power Only Physical Condition 7 / 10 Working Condition 10 / 10 ----------PURCHASING GUIDELINES:1) This item will be professionally packaged and insured for safe transit to your home unless you opt for local pickup from our shop. All local pickup items are only wrapped in industrial strength clear stretch wrap if the original manufacturer packaging is unavailable.Local pickup is available in Glen Rock, NJ, just a half hour drive from Midtown Manhattan, with convenient parking near our building.If we don’t have the original manufacture’s packaging, we use heavy duty double-ply corrugated boxes with custom made to your item SealedAir Instapak expanding foam custom inserts. In many cases this has proven to be better than the original packaging! We also use high quality fiber reinforced tape to seal our packages. Lightweight items will be bubble wrapped and shipped in a high-quality box. 2) We do not review or accept any offers that do not go through the official eBay system. We have too many items for sale and it is nearly impossible to keep track of offers outside of the official system. Please do not message, email, or text any offers. 3) All listings are eligible for the eBay Global Shipping Program, unless the item exceeds the maximum weight/price requirements to your country. If this is the case simply message us via eBay as we accept bank wire transfers for international payments and frequently ship worldwide via UPS.4) Please ensure your shipping address is correct within eBay as we will ONLY ship to the eBay/PayPal Confirmed Shipping Address. No exceptions.5) eBay may charge and collect sales tax to your state/jurisdiction. Please understand we have no control over this.eBay v1.5eBay integration by

Price: 2499 USD

Location: Glen Rock, New Jersey

End Time: 2024-02-05T19:42:08.000Z

Shipping Cost: 0 USD