Marantz Model 7 Vintage Tube Preamp - Full Restoration and Gorgeous
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Marantz Model 7 Vintage Tube Preamp - Full Restoration and Gorgeous
SkyFi 479
479 South Broad Street
Glen Rock NJ 07452
United States
** Sorry this sold 5 minutes after our 1/15/2021 email blast - we have others currently available on our site please click here to view.
This is a fully restored Marantz Model 7 fitted with the best vintage tubes you can get. Working like new, and sounding amazing.
The faceplate metalwork and knobs are absolutely perfect which is rare.
The metal golden painted top is free from scratches which we've also never seen before. Probably because it lived inside the wooden case its entire life.
Your purchase also includes the original warranty card and manual as show in our photos. WOW!
Notes from our Lead Technician:
This Marantz 7 came to us with a full complement of Telefunken ECC83 tubes. We tested them on our modern and professional Amplitrex AT1000 tester, and they all tested strong all with near 100% NOS Spec on gM. We also test for microphonics and all six tubes demonstrated the low microphonic and noise profile that we've come to expect from Telefunken tubes.
Restoration Outline:
This piece came to us from a collector that selected this specific preamp to be professionally restored. We reviewed the work in detail, and verified all functions with our usual range of tests (read more on this here).
The power supply was rebuilt with modern production multi-section cans, maintaining the original look. The original half-wave Selenium rectifier was left in place in the chassis, but a Silicon replacement was installed on a terminal strip beside the original. This offers the end user the option to switch back to the original rectifier if desired and is unique. A compensating resistor was not installed in either the main supply or filament supply for the new Silicon parts, so we encourage its new owner to operate this piece on a Variac at 117VAC to extend tube life.
The signal path capacitors in the main preamp section were also upgraded to film types, mostly from Illinois Capacitor. Select resistors were replaced as needed.
Check out our YouTube video from a different Marantz 7 we had previously listed for sale for more details:
From The Absolute Sound by Robert Harley "TAS Legacy: Marantz Model 7 Preamplifier:
"The Model 7 was a breakthrough in preamplifier design at its introduction in 1958. Largely engineered by Saul Marantz, the Model 7 offered dual phono inputs, two tuner inputs, and in a stroke of prescience, a “TV” input. In 1958. The front panel featured an array of four knobs on each side flanking four toggle switches. The right-side knobs provided independent bass and treble adjustment for each channel. The left-side knobs allowed source selection, volume, balance, and stereo/mono modes. The center toggle switches were tape monitor, a three-position phono equalization switch (78, Columbia, RIAA), and high- and low-pass filters. Minimalism in preamplifier design had clearly not yet taken hold.
The model number was not on the front panel, just the inscription “Marantz Stereo Console,” with the word “Stereo” in fancy script. The front-panel layout was created by Mr. Marantz, who had a background in drafting, graphic arts, and industrial design.
The circuit was based on three 12AX7s per channel. The phonostage was particularly innovative in its three-stage circuit, which was soon dubbed “the Marantz circuit.” Phono gain was 64.5dB (22.5dB line). The frequency response was 20Hz–20kHz +/- 0.5dB. Noise was -80dB with a 10mV phono input. The unit weighed 20 pounds.
In production for more than 12 years, the Model 7 was the most popular preamplifier of its time, with sales of more than 130,000 units—a staggering number considering its price of $385 ($3211 in 2016 dollars). Throughout its 12-year run, the Model 7 remained essentially the same as the prototype, with only minor production updates over the years. The Model 7C simply signified that the chassis was mounted in a wooden case."
Marantz Model 7 Instruction Manual
The SkyFi Testing Process for All Preamplifiers:
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 transistors are checked for signs of stress or damage. Special attention is paid to the power supply which is the most common source of failure for preamps. We then power up the unit and run a simple 1k sine wave while monitoring the low voltage output on an oscilloscope for signs of distortion or noise to get a baseline.
At this point we will lubricate and clean all switches and potentiometers (that are not sealed) with a high quality contact cleaner, and then re-test all functions for any signs of noise or scratching.
Final testing involves putting actual music through the preamplifier We have learned over time that some issues are only noticeable to a trained ear while listening to a familiar source material. Our test bench has reference vintage KEF speakers that we are super familiar with which will quickly reveal any discrepancies. Some preamps will then move into the listening room where they will be tested with our in-house reference system.
Please click here for detailed specifics regarding our specialized packing process that separates us from the rest.
Item |
Included |
Original Box |
No |
Manual |
YES + Warranty Card! |
Remote |
N/A |
Cables |
Yes - Power |
Physical Condition |
8 |
Working Condition |
10 |
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