Keith O. Johnson: Recording and Audio Engineer Extraordinaire

In Brief

Keith O. Johnson is a recording engineer whose more than 150 releases in classical and jazz include two Grammy winners and seven nominated for Best Engineered Classical Recording. Keith co-founded Gauss, Microsonics, and Reference Recordings, and holds any number of patents. He recently received a Silver Medal from the Audio Engineering Society at the 125th AES convention in San Francisco, California "for outstanding contributions sustained over 40 years, to the advancement of audio quality of recordings through innovation in the areas of analog and digital recording technology, transducers and music recording techniques." In addition he is a fellow and a Lifetime Member of the Audio Engineering Society.

KOJ studied computer science, biology, and music at UCLA, and did his graduate studies in electronics at Stanford University. For most of his life, for good and sufficient reason, his name has been prefaced by the honorific "Professor"; most of the high end community knows KOJ as Prof. Keith O. Johnson.


Keith de Osma Johnson (KOJ), born on March 29, 1938, was an only child who had an instinctive flair and passion for creativity and innovation from a young age. While he was in grade school, Ampex Corporation awarded him a scholarship and training program for his three-channel recorder and microphone project. He developed photolithography construction of magnetic heads at Stanford University in the sixties, consulted with Sherman Fairchild and applied his proprietary Focused Gap technology to master recorders and later to high-speed tape duplicators when he co-founded Gauss Electrophysics. “It literally revolutionized the whole field overnight,” according to Prof. Johnson.

Of particular interest to audiophiles and music lovers, while at Stanford University in the 1960s, Prof. Johnson created a solid-state 3-channel recorder that he used on more than 100 recordings. “It has 3.5-megahertz bias and still runs,” he says. “I thought that if I could focus the magnetic field onto the tape, I could get rid of some losses that normally occurred in recording. And it worked.”

Prof. Johnson went on to contribute his knowledge to the MCA DiscoVision video disc, engineered orchestral works for the Armed Forces Radio and conceived an optical CCD scanner, the Colortek system, which removes noise from damaged motion picture soundtracks. In the 1970s, he worked with rock band Ambrosia and partnered with producer Alan Parsons to develop the Projectron, one of the first tools to incorporate expressive polyphonic sampling.

In 1976, he joined producer Tam Henderson and Marcia Martin to form Reference Recordings, launching a legacy of high-end/half-speed mastered LPs and high-definition CDs (DDD). Prof. Johnson co-invented the HDCD technology with Pflash Pflaumer, and in 1996, they formed Pacific Microsonics to introduce the concept of high-resolution audio. In 2000, Microsoft purchased Pacific Microsonics and continues to incorporate HDCD technology into its PC offerings. Prof. Johnson subsequently consulted with Microsoft; one project, Speaker-Correction, uses modeled correction of speakers to improve computer sound and can be found in XP software.

In addition, as Director of Engineering for Spectral Audio Inc. for over 25 years, KOJ created the Vertical Dimension Topology, in which the electrical audio signal "drops down" into the amplifier circuitry along the Z axis to reduce to an absolute minimum noise-causing electromagnetic-field interaction. He also developed the Focused Power Geometry circuit architecture, a distributed array in which a separate power supply is physically located next to each output device of a Spectral power amplifier.

Most Notable Achievements

Renowned for his more than 50 pioneering years of recording and equipment design, Keith Johnson has always been at the forefront of high resolution audio. He has engineered nearly 150 classical and jazz albums including the aforementioned Grammys for Best Engineered Classical Recording. Other accolades include two NAIRD Indy Best Recordings and, from The Abso!ute Sound, two Golden Ear awards. Many consider his magnum opus to be his work on analog-to-digital and digital-to-analog conversion techniques, including his co-invention of HDCD.

His work with Spectral Audio has produced some very highly regarded preamps, power amps, digital-to-analog converters, and CD players. Though no longer manufactured, the Pacific Microsonics Model Two, of which he was the lead designer of, is still considered by many top recording and mastering engineers to be the finest Analog-to-Digital converter ever made.

In Summary

Prof. Johnson is a unique combination of:

  • world-class analog audio engineer - including circuit design and layout topology

  • world-class digital audio engineer - including circuit design and layout topology

  • highly knowledgeable in applied psychoacoustics

  • highly regarded recording engineer - designing the components in his own custom recording system

According to Robert Harley, editor of The Absolute Sound, “Keith Johnson is the co-inventor of HDCD, recording engineer of all the Reference Recordings projects, designer for Spectral, and has perhaps the most insightful audio mind of anyone working today.”



Recordings by Grammy winner & 11-time Grammy nominated classical recording engineer Prof. Keith O. Johnson


2011 Best Surround Sound Album (for vocal or instrumental albums) at the 53rd Annual Grammy® Awards.

  • Reference Recordings multi-channel Britten's Orchestra (Note: This recording of this performance is available in a variety of formats: SACD hybrid multi-channel, PCM-based two-channel CD, 44.1/16 and 88.2/24 downloads from HDTracks, and as a 176.4/24 HRx DVD-R master from Reference Recordings. At some point it is expected that the 176.4/24 surround version will be made available too.) link for more info

GRAMMY WINNERS engineered by Keith O. Johnson

  • ARGENTO: Casa Guidi (Reference Recordings RR-100) Eiji Oue and the Minnesota Orchestra (2003). [In addition mezzo-soprano Frederica von Stade was nominated in the category "Best Vocal Performance," and composer Dominick Argento was nominated for "Best New Classical Composition"]
  • BRUCKNER: Symphony No. 9 (Stanislaw Skrowaczewski/Minnesota Orchestra), (Reference Recordings RR-81)

GRAMMY® NOMINATIONS ("Best Engineered, Classical") engineered by Keith O. Johnson:

  • RACHMANINOFF (Reference Recordings RR-96) Eiji Oue and the Minnesota Orchestra (2001)
  • RESPIGHI  Eiji Oue and the Minnesota Orchestra  (Reference Recordings RR-95) (2000)
  • MALCOLM ARNOLD OVERTURES (London Philharmonic Orchestra conducted by the composer), (Reference Recordings RR-48)
  • BOLERO (Eiji Oue/Minnesota Orchestra), (Reference Recordings RR-92)
  • STRAVINSKY: The Rite of Spring, The Song of the Nightingale, The Firebird Suite (Eiji Oue/Minnesota Orchestra), (Reference Recordings RR-70)
  • CHICAGO PRO MUSICA ("Best New Classical Artist') (Reference Recordings RR-2102)


  • RACHMANINOFF: Symphonic Dances, etc. (Eiji Oue/Minnesota Orchestra), (Reference Recordings RR-96)
  • RIMSKY-KORSAKOFF: Scheherazade, etc. (Jose Serebrier/London Philharmonic Orchestra),  (Reference Recordings RR-89)


  • BRUCKNER: Symphony No. 9 (Stanislaw Skrowaczewski/Minnesota Orchestra), (Reference Recordings RR-81)
  • FROM THE AGE OF SWING (Dick Hyman),  (Reference Recordings RR-59)
  • ARNOLD OVERTURES (Arnold/London Philharmonic Orchestra),  (Reference Recordings RR-48)

NAIRD "INDY" AWARDS ("Best Original Recording")

  • RESPIGHI: Belkis, Queen of Sheba, etc. (Eiji Oue/Minnesota Orchestra) (Reference Recordings RR-95)
  • TRITTICO (Frederick Fennell/Dallas Wind Symphony), (Reference Recordings RR-52)




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