The Internet's Quadraphonic Place

written by Klaus Hönemann, Aug. 2017
Thanks to Colja P., who helped me to translate the text.

In addition to JVC's "1000 system", the "MM-4 Memory Meter" is certainly one of the most sought-after or rarest devices in the "Quadro scene". It was therefore a special day in August 2017, when Quadro-friends Eric Prasse from Switzerland, Georg Kessen and I could test this device for two days at my place.

--> for urgent readers: YouTube link

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The MM-4 has a screen that can optically display the modulation of the four channels of the Quadro field. He who opens up the MM-4 will be quite astonished at first, since one would suspect a "tube" having been installed in a device built in the late 1970s. But actually there's a plasma screen already being utilized here. So we're presumably talking about one of the first devices with this technology ever.

MM-4 off

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One that suspects a great number of ways to connect accessories, as is usually the case with Quadro devices, will be disappointed with the spartanly tidied up back of the MM-4, too. Only four cinch inputs for the four channels and a fixed power cord are provided.

Also a conversion to 220 or 240 volts is not possible, so we had to operate the device with a ballast transformer, which supplied the line voltage of 110 volts commonly used in Japan.

Serial-number unrecognizable on request of the owner

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This shows a tone sounding from the right front.

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Seeing the MM-4 „at work“, you will be attracted magically by the play of the four circles. Therefore here's the link to the You-Tube video showing the device in action.