After graduating from university, Reis contacted several of the companies he had visited at the Berlin show while looking for a job. MBL met with him and offered him a position. At the time, the company was marketing the Model 100 loudspeaker, the brand-new 4010 preamplifier, and the six-month-old 4020 parametric equalizer. The equalizer was necessary because the loudspeaker’s frequency response was so uneven that it had to be corrected.

After a few weeks at the company, Reis asked whether he could bring in a preamplifier he had built while studying in Frankfurt. Because he had not had access to sophisticated measuring equipment, he had designed it according to what he thought and felt ought to be right. He was curious to see how it would perform on MBL’s suite of Hewlett-Packard test equipment.

As it turned out, Jürgen’s preamplifier measured far better than MBL’s newly released 4010. Mr. Lehnhardt—the “L” in MBL—and Mr. Meletzky—the “M”—were so impressed that they immediately put Reis in charge of developing all future electronics. Unsurprisingly, his first assignment was to design a new preamplifier, the 5010, which later evolved into the legendary 6010, now in its 6010 D iteration.

After two years at MBL, Reis began working on the Radialstrahler loudspeaker, using carbon fiber to design a new tweeter. The Model 100’s original tweeter and midrange membranes were made from slices of aluminum, but the metal gave the loudspeaker a highly colored sound. Reis sought a material that would reduce coloration and distortion while producing a smoother, broader frequency response. It took him more than a year to perfect the new carbon-fiber tweeter. He then applied the same techniques to the midrange driver.

Thanks to Reis, MBL was able to introduce a greatly improved Radialstrahler in 1986: the now-famous MBL 101, with carbon-fiber tweeter and midrange drivers. The initial reaction from the audiophile press and community resembled Jürgen’s own first response to the Radialstrahler. “People liked the 101, but they didn’t understand why they liked it,” he recalled. “They had simply never heard anything that transparent—anything that sounded so much less like a loudspeaker.”

That transparency—and Reis’s own genius—helped him develop MBL’s standard-setting electronics, including the company’s first Reference amplifier, the 9010, and, in time, the 1611 Reference D/A converter and 1621 Reference CD transport.

In 1990, Reis began developing the Reference Line amplifier using his ingenious “4QT” test to measure performance. He was exceptionally hands-on in his development work, creating everything himself: the schematic, the layout, the printed circuit board, and all the hand drilling and assembly. The result was the remarkable 9010 monoblock. The current 9011 is a further development of that design and can verifiably drive any phase relationship between voltage and current.

In 2005, Reis started his own recording studio and became an Apple Certified Mastering Engineer. The work required true high-resolution files—24-bit/96kHz recordings with no sample overs or intersample overs, and therefore no distortion introduced in the conversion from analog to digital and back again.

At the time, the “Loudness War” was well underway. “Each CD got louder and louder,” Reis said, “and I realized that, when listening to a D/A converter, the sound was often harsher, brighter, and more aggressive than the measurements suggested it should be. Sinewave distortion might tell us everything was fine—that there was no clipping—but, as with the 4QT test, you needed to use a complex signal, like real music.”

Reis therefore developed what became known as the “Reis test” to measure what he was actually hearing. He discovered that music could drive a D/A converter into clipping even when conventional measurements did not reveal the problem.

“When I tested the 10 most popular CDs in Germany, I found approximately 1.5 million intersample overloads in total,” he said. “On average, the signal was clipping 50 times per second. This is why digital can sound harsher than a regular THD measurement would indicate.”

After learning through the Reis test that nearly all new releases produced intersample overloads in the DAC, Jürgen resolved that MBL DACs would not pass those overloads along, even when the recordings themselves contained overs. “You can play CDs on any MBL DAC and have no intersample overloads, because I devised a way to build in headroom.” MBL DACs are immune because Reis developed a method to test for—and hear—the overloads.

During his 44 years with MBL, including 42 years as chief engineer, Reis designed 10 preamplifiers, 14 power amplifiers, six integrated amplifiers, and more than 30 MBL loudspeakers. Replacing him will be next to impossible. How does one replace an honest-to-goodness genius?

Of course, MBL will not be the first audio company compelled to confront the retirement of a star engineer or founding father. It is our hope—and Jürgen’s—that the company will continue to prosper under the guidance of a new leader who can take MBL to the same engineering heights that Jürgen achieved.

It is also our sincere hope that Jürgen enjoys the retirement he has so richly earned. Speaking for myself, Jürgen, I wish you only the best, because you are the best—the single most brilliant and inventive equipment designer it has been my honor to know.