Conrad Johnson MV52 Tube Amplifier

Description: Conrad Johnson MV52 Tube Amplifier - Factory Upgraded WHO WE ARESkyFi 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.----------The MV50 is one of our most beloved and versatile tube amplifiers from CJ. The MV52 takes it to the next leveI. Our in-house tube expert went through this amplifier carefully to ensure it meets full and original factory performance. PLUS this example was factory upgraded from an MV50 to MV52 in August 1993. Tube Notes: (4) Matched Quad New Svetlana EL34 (2) Philips ECG 6CG7 (2) GR 5751 Cosmetic Notes: • Right channel terminal block has some minor damage.• Left handle slightly bent but barely noticeable.Great bit of info from CJ:CIRCUIT DESIGNIt has been our experience that simple designs with few active stages when executed with care and great attention to detail will be both more musical and more reliable than overcomplicated alternatives.Accordingly, the audio circuit of the MV52 is remarkably straightforward.A triode input amplifier comprised of paralleled sections of a 5751 is directcoupled to a cathode coupled differential phase inverter using high current triodes to provide balanced, low impedance drive to the pushpull output stage.The output stage features ultralinear operation which permits high power levels while greatly reducing the source impedance of the stage.As a result, the amplifier is capable of supplying the large current demands of high amplitude musical transients driven into reactive speaker loads.A substantial main power supply of massive polypropylene capacitors enables the MV52 to easily meet these extraordinary current demands.Voltage regulators for the voltage amplifiers and phase inverters provide nearly absolute isolation of these sensitive stages from the output stages.SPECIFICATIONS:Power: 45 watts per channel RMS both channels driven into 8 ohms from 30Hz to 15KHz at no more than 1% total harmonic distortion or intermodulation distortion.Sensitivity: 750 mv to full power.Small Signal Distortion: Less than .1% at midbandPhase: Phase correct (non-inverting)Frequency response: 20Hz to 20KHz +0, -.5dBHum and noise: 90dB below full power output.Input impedance: 100K ohms.Dimensions: 11.5D x 19W x 9H inches.Weight: 39 lbs.The SkyFi Testing Process for Tube Amplifiers:We start with a visual inspection of all internal components to make sure there are no signs of stress or aging. Capacitors are checked for telltale sings of bulging or leaking, resistors are checked for signs of overheating or cracking, and tubes are inspected for signs of stress overheating or cracking.We then power up the unit carefully and run a simple 1k sine wave while monitoring the output on an oscilloscope for signs of distortion or noise. Finally we run the amplifier to its full rated power into the appropriate resistive load provided by our Sencore amplifier tester. If there is an issue, it will usually be noticeable at this point. If it all looks clean we will often test for THD (Total Harmonic Distortion) measured by our Keithley distortion meter, and compare it against the original manufacturers specifications. The amplifier the remains powered on to "burn in" on our test bench for a few hours to make sure there are no heat related issues. If there are balanced inputs available they will also be tested.We also test all tubes for output gain and leakage on our modern and professional tester against the original manufacturers specifications. If needed, the tubes will be replaced from our vast NOS (New Old Stock) vintage or modern inventory.Final testing involves pushing actual music thorough the amplifier. We've learned over time that some issues are only noticeable to a trained ear while listening to familiar source material. Our test bench has reference vintage KEF speakers that we're very familiar with which quickly reveal any discrepancies. Some amplifiers will then move into our listening room where they are tested with our in-house reference speakers of choice. Item Included Original Box Not Included Manual Online Only Remote Not Applicable Cables Yes - Power Physical Condition 7 Working Condition 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 v1.5 WHO WE ARESkyFi 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.---------- The MV50 is one of our most beloved and versatile tube amplifiers from CJ. The MV52 takes it to the next leveI. Our in-house tube expert went through this amplifier carefully to ensure it meets full and original factory performance. PLUS this example was factory upgraded from an MV50 to MV52 in August 1993. Tube Notes: (4) Matched Quad New Svetlana EL34 (2) Philips ECG 6CG7 (2) GR 5751 Cosmetic Notes: • Right channel terminal block has some minor damage.• Left handle slightly bent but barely noticeable.Great bit of info from CJ: CIRCUIT DESIGN It has been our experience that simple designs with few active stages when executed with care and great attention to detail will be both more musical and more reliable than overcomplicated alternatives.Accordingly, the audio circuit of the MV52 is remarkably straightforward.A triode input amplifier comprised of paralleled sections of a 5751 is direct coupled to a cathode coupled differential phase inverter using high current triodes to provide balanced, low impedance drive to the pushpull output stage.The output stage features ultralinear operation which permits high power levels while greatly reducing the source impedance of the stage.As a result, the amplifier is capable of supplying the large current demands of high amplitude musical transients driven into reactive speaker loads.A substantial main power supply of massive polypropylene capacitors enables the MV52 to easily meet these extraordinary current demands.Voltage regulators for the voltage amplifiers and phase inverters provide nearly absolute isolation of these sensitive stages from the output stages. SPECIFICATIONS: Power: 45 watts per channel RMS both channels driven into 8 ohms from 30Hz to 15KHz at no more than 1% total harmonic distortion or intermodulation distortion. Sensitivity: 750 mv to full power. Small Signal Distortion: Less than .1% at midband Phase: Phase correct (non-inverting) Frequency response: 20Hz to 20KHz +0, -.5dB Hum and noise: 90dB below full power output. Input impedance: 100K ohms. Dimensions: 11.5D x 19W x 9H inches. Weight: 39 lbs.The SkyFi Testing Process for Tube Amplifiers:We start with a visual inspection of all internal components to make sure there are no signs of stress or aging. Capacitors are checked for telltale sings of bulging or leaking, resistors are checked for signs of overheating or cracking, and tubes are inspected for signs of stress overheating or cracking.We then power up the unit carefully and run a simple 1k sine wave while monitoring the output on an oscilloscope for signs of distortion or noise. Finally we run the amplifier to its full rated power into the appropriate resistive load provided by our Sencore amplifier tester. If there is an issue, it will usually be noticeable at this point. If it all looks clean we will often test for THD (Total Harmonic Distortion) measured by our Keithley distortion meter, and compare it against the original manufacturers specifications. The amplifier the remains powered on to "burn in" on our test bench for a few hours to make sure there are no heat related issues. If there are balanced inputs available they will also be tested.We also test all tubes for output gain and leakage on our modern and professional tester against the original manufacturers specifications. If needed, the tubes will be replaced from our vast NOS (New Old Stock) vintage or modern inventory.Final testing involves pushing actual music thorough the amplifier. We've learned over time that some issues are only noticeable to a trained ear while listening to familiar source material. Our test bench has reference vintage KEF speakers that we're very familiar with which quickly reveal any discrepancies. Some amplifiers will then move into our listening room where they are tested with our in-house reference speakers of choice. Item Included Original Box Not Included Manual Online Only Remote Not Applicable Cables Yes - Power Physical Condition 7 Working Condition 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: 3229 USD

Location: Glen Rock, New Jersey

End Time: 2024-03-01T21:48:56.000Z

Shipping Cost: 0 USD