1965 EAB RE85: 8 x 2 Tube Mixing Console
Several years ago we were contacted by Genuine Sound in Chicago regarding the service for their newly acquired 1965 EAB 8 into 2 tube mixing console. Several phone conversations later, we sent one of our technicians to Chicago to take a closer look. Upon further inspection, it seemed that the console was in a very poor condition and needed to be shipped to us for the actual repair work.
As soon the console arrived here, we took it apart to get a basic idea of the work that would be required to bring the console back up to spec. A phone call to the ZDF television station in Germany revealed more historic details of the EAB RE85.
Originally made for the ZDF in 1964, it was mainly used for monitor support in TV specials, like sports and concert shows. Compared to the standard version of the RE85 (approx. 300 were made), it was a stripped down version; just 8 channels into two with passive hall plate send on each channel. Several different output options were disconnected by the 2nd owner, that had purchased the unit somewhere between 1980 and 1984 from the TV station. In addition to the missing output options, several major modifications were made. These mods had seen minor use due to the fact that most of them were just passive and too noisy.
It turned out that six of the eight VE12P modules had damaged or burned out input x-former (someone had improperly tried to use phantom power on the channels), defective switches and pots, etc. Compared to the damage in both of the two power supplies and the main frame, these were considered small problems.
All of the VE12's were rebuilt to the original specs with a few minor upgrades in the input stage and hall sending section. Nearly all of the input transformers needed to be rewound with new shock mounts and higher insulation resistance so that in the future, +48V phantom power would not be a problem. The VE12 circuit is very similar to Telefunken V101/102 mic-pre's with a two band +/-9dB EQ and a Danner fader module. A max. gain of 60dB is accomplished by two DC heated Valvo made E283CC, a very low noise version of the E83CC ( the pin layout is different). The only disadvantage of this tube is that if overdriven the E283CC just shuts off, making the light meters very handy...
The main frame was a disaster! All of the routing functions, meter sections, etc. were in a bad state of disrepair. Instead of patching up the disconnected sections and power supplies, we decided to rewire it completely. We added a few options like XLR connectors, phantom power and a beefed up 24V 5A power supply. The two high voltage power supplies needed complete rebuilding and while doing so changed over to 120V. The previous owners had added pan sections to four of the channels, but they proved to be ineffective and too noisy. A completely new active pan pot for every channel was installed. The standard left/right out switches were replaced with conductive plastic dual pots, insuring a smooth pan with minimal cross-talk. Two new V372s were built into the custom made channel housing, to take care of the summing part in the pan section. This gave the console a better S/N ratio than it would normally have.
We also found enough space in a 2nd channel housing for eight more V372s that provide a balanced post fader (+4dB) recording out for each VE12. S/N unweighted is an average of -90dB @60dB setting.
A 3rd channel houses three new V376S mic pres for PFL and an additional left right monitor out.
Both VS21 main modules were rebuilt by the previous owner and were the only good working parts of the console. The basic circuit is very similar to the Telefunken V41 mic pre, but instead of EF12's, three very low noise EF806s (the same type we use in our V72S) do the 47dB end boost, controlled via a Danner made fader. Plate choke and output x-former are identical to the V41. Aside from minor adjustment and tube replacement we could use them as they were.
Rebuilding, cleaning, rewiring, modifications and metal work, we finished the work after nearly six weeks of work. The end result is quite amazing. Now it is technically an entirely new console looking like a historical EAB RE85. High voltage power supplies sit on the left and right. The two Black Boxes on the right, house the 24/48V power supply and the eight V372s recording amps, the other one on the right the PFL and mains monitor buffer. From a sonic perspective, it sounds very close to a V72/76 based board, with different mid range response, but definitely a smooth tone that you would want from a desk like this. With a matched pair of Studer J37 the Genuine Guys have the perfect classic recording set-up.
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