John Ulrick on the cover of Positive Feedback, Vol. 6, No. 4, 1996
Today I mourn the passing of a good friend and one of the men who helped found the high-performance audio industry, John Ulrick. Hired as a Circuit Design Engineer at Litton Industries right out of college to work with the Air Data Group, John started designing servo circuits for the North American XB-70's Mach number computer in 1962.
It was there that he met future Infinity partner, Arnie Nudel in 1965. Working together in the Litton applied physics group doing solid-state laser research, Arnie asked John to design the switching power supply and servo to control the mirror that would point the laser for their new range finder.
Litton was already using early Class-D amplifiers to control the gimbals of the inertial platforms of their navigation systems. While measuring the pointing servo, Arnie asked John if he might be able to apply servo control to a woofer. John found that an intriguing idea and set to work producing a servo control system for a customized Cerwin-Vega 18-inch woofer with a feedback winding. The use of servo control extended the bass lower by three octaves and reduced the harmonic distortion by a factor of ten! This system would evolve to become the Servo-Static I, and the first commercial models was sold in 1966 under the name NUTEC.
By August 1968, Infinity was born and John soon found himself asking if he could build an audio amplifier using switching technology. The resultant amplifier, which he called The SWAMP (SWitching AMPlifier), yielded 250 watts per channel, ran at a switching frequency of 500 KHz, and was the first audio Class-D amplifier in the world.
After selling infinity in 1974, then leaving after contractual obligations in 1978, John started Spectron, and for the first five years built stereo automotive amplifiers. Japanese competition grew so fierce by the end of the decade that they just couldn't compete, so John and some of his former colleagues from Hughes Missile Systems started building a multiplexer system to double the capacity of each satellite transponder for the burgeoning satellite TV business. They licensed and sold it, and John, with a little cash back in his pocket, re-started Spectron in 1990.
This time, he wanted to build Class-D amplifiers for the audiophile market. His first commercial product, a digital pulse width modulation-switching amplifier, the Spectron 1KW, was a 500 watt per channel stereo behemoth, and was well received by the audiophile community in 1992. Over time, the 1KW continued to evolve, first reintroduced as the Musician in 2000, then, with minor but very effective improvements in the circuit, it was released as the Musician II in 2003. John advanced the design to offer the Musician III by 2005, a 600Wpc amplifier that set new standards for the class, and most recently offered a Musician III Mk2, that incorporated V-Cap Upgrades, Super-Effect Bybee Purifiers, and cryogenically treated ceramic CryoParts Rail Fuses, first available in 2014.
Most recently, John spent the better part of his day designing special versions of his class-D amplifier circuits for license to semiconductor companies, who in turn manufacture the amplifier on semiconductor chips for pro sound power amplifiers and premium auto sound systems.
John had successfully won a bout with prostate cancer late last summer, but over the past 8 weeks he had been in and out of the hospital. His cancer finally affected his brain, and John passed away last night (May 20, 2015), at approximately 7:30 PM, with his sister-in-law, Beverly Larkin, by his side at the Henry Mayo Newhall Memorial Hospital in Valencia, California. He was one of the true gentlemen of this industry, and his friendship, his almost permanent smile, his effervescent outlook on life, his unrelenting love of auto racing and audio, will be sorely missed and impossible to replace.
Born August 19, 1939, and raised in Encino, California, the wife he adored and shared his life and passions with for 22 years, Toni Decker, passed away in 2013. He is survived by three stepchildren, Kevin Decker, Eva Rejhons, and Nick Decker, and two grandchildren, Sam Casey and Noa Rejhons.
