Description
Mark Levinson No. 380S Dual Mono Preamp - Factory Serviced Mark Levinson No. 380S Dual Mono Preamp - Factory Serviced General: The 7270 is by FAR one of our favorite vintage amps from McIntosh and by far one of our most popular sellers. They are easy to service, super reliable and built to last a century. Aesthetically it meets all the requirements - large chassis, big blue meters, glass & metal faceplate, and BIG power. This particular sample is in great shape and passed all of our internal tests with ease. SkyFi Cosmetic Notes: • Perfect Glass Faceplate. • Light blemishes on top metal surfaces and sides. • Lighting is original incandescent. *Entire faceplate is a condition 8-9 and so is the top, but the sides do have a few scratches bringing overall condition to 7. SkyFi Service Notes: • Glass Replaced w/McIntosh Factory Official Replacement. • Controls Cleaned. • DC Offset and Bias Adjusted to Service Manual Specification. • Meter Watt / Hold Switch Replaced. • Meters Calibrated. Brand Background: McIntosh Laboratory is an American manufacturer of handcrafted high-end audio equipment based in Binghamton, New York. The company was founded in 1949 by Frank McIntosh. The company designs and produces audio amplifiers, stereo tuners and other consumer electronics products. Ownership: Single Owner Connections: RCA inputs, Screw Terminals for Speakers, Captive Power Cord General Sound: Big beautiful musical sound with little fatigue. Cosmetic Condition: 7/10 = Good. One or two minor scratches. Well Maintained. See our detailed rating description here. Working Condition: Working perfectly and tested in our lab and listening room. Included: Just the unit and power cord. Packing: Original Manufacturers Packing Specs: PERFORMANCE GUARANTEE Performance Limits are the maximum deviation from perfection permitted for a Mclntosh instrument. We promise you that when you purchase a new MC 7270 from a Mclntosh franchised dealer, it will be capable of or can be made capable of performance at or exceeding these limits or you can return the unit and get your money back. Mclntosh is the only manufacturer that makes this statement. PERFORMANCE Mclntosh audio power ratings are in accordance with the Federal Trade Commission Regulation of November 4, 1974 concerning power output claims for amplifiers uséd in home entertainment products. POWER OUTPUT STEREO 270 watts minimum sine wave continuous average power output, per channel, both channels operating into 1 ohm, 2 ohms, 4 ohms, or 8 ohms load impedance, which is: 16.4 volts RMS across 1 ohm 23.2 volts RMS across 2 ohms 32.9 volts RMS across 4 ohms 46.5 volts RMS across 8 ohms MONO-BRIDGE 540 watts minimum sine wave continuous average power output into 2 ohms, 4 ohms, 8 ohms, or 16 ohms load impedance, which is: 32.9 volts RMS across 2 ohms 46.5 volts RMS across 4 ohms 65.7 volts RMS across 8 ohms 93.0 volts RMS across 16 ohms OUTPUT LOAD IMPEDANCE STEREO 1 ohm, 2 ohms, 4 ohms, and 8 ohms; separate terminals are provided for each output. MONO-BRIDGED 2 ohms, 4 ohms, 8 ohms, or 16 ohms, balanced to ground. RATED POWER BAND 20 Hz to 20,000 Hz TOTAL HARMONIC DISTORTION STEREO 0.02% maximum harmonic distortion at any power level from 250 milliwatts to 270 watts per channel from 20 Hz to 20,000 Hz, both channels operating. MONO 0.02% maximum harmonic distortion at any power level from 250 milliwatts to 540 watts from 20 Hz to 20,000 Hz. INTERMODULATION DISTORTION STEREO 0.02% maximum if instantaneous peak power output is 540 watts or less per channel with both channels operating for any combination of frequencies, 20 Hz to 20,000 Hz, MONO 0.02% maximum if instantaneous peak power output is 1080 watts or less for any combination of frequencies, 20 Hz to 20,000 Hz. FREQUENCY RESPONSE (AT ONE WATT OUTPUT) 20 Hz to 20,000 Hz +0 -0.25 dB. 10 Hz to 100,00 Hz +0 - 2 dB. NOISE AND HUM 100 dB below rated output. RATINGS DAMPING FACTOR Greater than 30 INPUT IMPEDANCE 20,000 ohms. INPUT SENSITIVITY Switchable: 0.75 volt or 2.5 volts-level control provided for higher input voltages. POWER GUARD Clipping is prevented and THD does not exceed 2% with up to 20 dB overdrive a 1 kHz. GENERAL INFORMATION POWER REQUIREMENTS 120 volts 50/60 Hz; 13 amps. SEMICONDUCTOR COMPLEMENT 79 silicon transistors 31 silicon rectifiers and diodes 7 integrated circuits MECHANICAL INFORMATION SIZE 16 3/16 inches wide (41.1 cm) by 7 1/8 inches high (18.1 cm) by 14 1/2 inches deep (36.8 cm), including connectors. Knob clearance required is 1 1/4 inches (3.2 cm) in front of mounting panel. FINISH The front panel is a combination of glass and black anodized aluminum. The chassis is black. Dimensions: 16 3/16 inches wide (41.1 cm) by 7 1/8 inches high (18.1 cm) by 14 1/2 inches deep (36.8 cm), including connectors. Knob clearance required is 1 1/4 inches (3.2 cm) in front of mounting panel. Weight: 82 lbs. Testing Process: 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. If the amplifier passes visual inspection, we move on to a controlled power on sequence using a Sencore safety analyzer to monitor current draw in real time. Once the amplifier is determined to be safe to operate, we connect it to full AC mains for function and power testing. We connect the speaker outputs of the amplifier to a Sencore PA81 Power Analyzer which acts as a dummy load, DC offset monitor, and oscilloscope interface. We start with a low level 1KHz test signal at the amplifier’s input and slowly increase its amplitude while monitoring the output on an oscilloscope for signs of noise, clipping, distortion, or improper channel balance. We continue increasing the signal level until the amplifier reaches clipping. At this point we take an output power measurement and compare it to the spec sheet of the amplifier to verify proper performance. If the device under test has both balanced and single ended inputs they are both tested at this time. We finish off the bench evaluation with a 1KHz square wave check and a 20Hz to 20KHz sine sweep to assess the amplifier’s frequency response characteristics. This battery of tests will usually reveal if the amplifier has any issues that need further attention. Before the device leaves the bench, we perform a listening test with actual music using a variety of preferred test tracks. Our benches are outfitted with familiar monitor speakers which help us identify inconsistencies that will not always show up on our test gear. The main things that we are listening for are hum or noise with no signal present, proper center image, clicks, pops, or any other obvious undesirable audio characteristics. If the unit passes all of these tests it is moved to our long term testing rig where we simulate real word operating conditions for 6-8 hours. This allows us to monitor the unit for signs of thermal runaway or intermittent issues that only crop up when the unit has fully come up to temperature. *Scroll down to view additional images for this listing and click to enlarge. **Please note we are not a repair shop and only restore what we own. ---------- SkyFi Audio - Curators of Vintage Audio Gear SkyFi 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. Please note we are not a repair shop and only restore what we own. ---------- 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, 07452, just a half hour drive from Midtown Manhattan, with convenient parking near our building. If we don’t have the original 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 will not review or accept any offers that do not go through the official eBay system. We have too many items for sale and it’s 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. We only 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 which we have no control over. eBay v1.8 × × × × × × × × × × × × × × × × × × Buy now and save! Tell a friend Visit store Watch now Postage info UPS Ground - $0.00 Local Pickup - $0.00 Click the Postage tab above the listing description for more info Additional delivery notes PICK UP OPTION Our items are available for pick-up. Pick up procedure is as follows: Purchase the item through eBay Email us to coordinate pickup PAYING VIA PAYPAL We accept PayPal on our all our items so you can shop with confidence. Simple choose the PayPal option when proceeding through the checkout. Additional Information No additional information at this time Ask seller a question You might also like Dynavector 10x3 High-Output MC Phono Cartridge Music Reference RM-5 MK II Tube Preamplifier with Phono Music Reference RM-9 Tube Amplifier With EL34s Marantz Model 150 Vintage AM/FM Tuner with Scope Contact To contact our Customer Service Team, simply click the button here and our Customer Service team will be happy to assist. Ask seller a question © SkyFi Audio Postage Click the Postage tab above the listing description for more info Payment Accepted Payment Methods PayPal Returns Returns are not accepted Seller will pay for return shipping. eBay integration by
Live search