Interelectronics Coronation 400 6L6 Tube Monoblock Pair - Restored - Ultra Rare

Description

Description
Here for sale a very rare pair of Interelectronics Coronation Four Hundred 40W Broadcast Amplifiers. These pieces are extremely rare as they were only produced for a short period of time. Interelectronics was an NYC based McIntosh competitor that produced a variety of HiFi components in the 1950s. Before the company really had a chance to take off on the HiFi side of things, however, they shifted into military and aerospace contracting and stopped producing audio amplifiers. These amps were designed and produced in the monophonic era, making it even more difficult to locate stereo pairs. Please see the video below, featuring this exact set for more historical context and restoration info.
CLICK HERE TO WATCH VIDEO!
Cosmetic Notes: These amplifiers are really quite impressive to look at but do have some cosmetic blemishes due to age. The chrome does show some rust and pitting in spots, the silk screen lettering is compromised in certain areas, terminal blocks have some damage, and there are some markings and discolorations on the transformers. Please review the images and video carefully for full detail. Note: The spade to banana adapters that are shown in some photos are not included.
Operational Notes: These amplifiers sound fantastic. They also feature a variable damping control which can be used improve amp/speaker synergy. Please recognize that these amplifiers were designed in a time when 117VAC mains were common. I recommend running these amplifiers on a variac or autoformer to reduce stress on the power transformers. After running these amps at 123V mains for more than 6 hours the power transformers get hot to the touch.
Restoration Outline:
All electrolytic capacitors replaced
All paper bumble bee caps replaced
Negative bias diode added to module socket to ensure proper negative bias voltage
Cathode fuse and 1/4W 10 ohm safety resistor added to protect output transformers in the case of tube failure
Bias set to service manual spec at 123VAC input
Perforated metal bottom covers and feet installed
Damaged power cords replaced
Rotary power switches added
Safety capacitors added to AC Mains input
NTC Thermistor added to reduce inrush current at power on
Retubed with current production Tung Sol 6L6GC, Electro Harmonix & Sovtek Rectifiers and Drivers.
Each amp bench tested to 30W before clipping 1KHz Sine (40W advertised spec only reachable with elevated mains voltage which causes unsafe operating conditions - the 40W rating was likely marketing hype in an era where specifications were not as closely regulated by the FTC)
Payment
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Returns
No return offered for this listing.
Shipping
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Note:
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Sales Tax
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