Ultra Fidelity Introduces its line of Electronics The


Featuring the finest “State of the Art” amplifiers of all time, restored & lifted to truly un-compromised performance by Myself. Using ALL the techniques I have learned over the last 40 Years. The Men of science unit’s were & are the time tested TRUE GREAT’s of all time.

The Krohn-Hite story and my search for the ultimate in sound & music.

Have You Ever wondered why such super companies as H.P., Western Electric, Altec, RCA, Gates, Tektronics or General Radio, never made a Super, Super, tube Amp? What I am talking about is using the Big & powerful resources that a major company has, the BEST, most famous engineers, and the most sophisticated no compromise design to make a truly advanced, superior amplifier. One that is far, far, above & beyond the entire world of the Hi-Fi consumer universe & it’s so called “luminary’s”. Even beyond everything ever done in Japan!

Well, there were such unit’s made. As with the building of Vintage Tube Services, I did much long hard research & by sheer grit, drive & some luck found them. When looking back, EVERYONE ((especially when they find out who was the designer is, will think, How did these get missed!!!))

Now after quietly collecting every unit I could find over the last 30 Years ((again as with V.T.S., 30 YEARS of learning, studying & perfecting techniques)) I have now mastered them & have enough of them to put together nice fully matched pair’s for the ultimate enjoyment of music!

These Historic amp’s will only be available until the dozen or so set’s are sold.

Who would be interested in such amp’s? Those interested in hearing & enjoying the finest, most refined, & yet at the same time the fastest & most vivid & music machines ever made.

I will spare You any more audiophile blather words, however I will share an odd effect that I have NEVER had with any other amplifier in 40 Years of collecting & auditioning amplifiers (including listening to these for about 30). I still say to myself each time when putting these on (mostly, I think because of their speaker damping & massive lack of inter-transit noise.) Is this the same recording I put on? It sounds so different it must be a different record!

If You are interested in auditioning them call me.


Andy Bouwman

Ultra-Fidelity Audio (616) 794-9680

Vintage Tube Services (616) 454-3467

The Krohn-Hite corp. has been & is still a world leader in state of the art Precision Calibration, Precision Phasemeters, Distortion Analyzers and Ultra Low Distortion, Wideband Power Amplifiers. You probably would not want to spend an evening listening to their current solid state offerings but the unit’s that were designed by the famous Mr. Richard Burwen in 1953 at the age of 26, just graduated out of Harvard University (( once properly re-built )) will put a smile on your face, year after year, for life!


  • The most technically advanced circuit ever developed for an audio amplifier!
  • Frequency bandwidth +db 0.03 cps to 80k!
  • Phase shift 2 degrees max. 0.5 cps to 30k.
  • Dynamic range 110 db
  • Distortion ratings that look more like a solid state amplifier than a tube unit!
  • Output rise under 5 microseconds

Construction Details

  • All parts made in USA and Germany by the all time classics
  • Main Electrolyitcs are all computer grade by CD Mallory & Sprague from 1980 to 2004 (Pre-changeover).
  • All signal caps are vintage glass seal oil
  • Main buckets are vintage oil transmitting & high current wired.
  • Power Sw is a true industrial electroswitch from Weymouth MA & still made!
  • DOUBLE choke & cap in series on power supply.


1940’s Early Years

When the government shut down ham radio for security reasons during World War II Dick became interested in hi-fi sound reproduction. In college and graduate school at Harvard, Dick’s adviser was F. V. Hunt, inventor of the first low-pressure phono pickup.  Dick was inspired to spend every afternoon in the Physics Library reading every article in every publication that had anything to do with acoustics and music recording and reproduction.


During the summer of 1949 between semesters, at Bell Laboratories, he designed a tracking band-pass filter.


Krohn-Hite Corp. Ultra-Low distortion Power Amplifier, model UF-101. 50 watts at 0.005% distortion from 4 – type 6550 output tubes produced for 20 years as a laboratory instrument, designed by Dick.


In September 1961 Dick quit his job at Honeywell to become a full-time circuit design consultant, working at his well equipped home laboratory for more than 60 different companies during the next 42 years.


Pioneer Spacecraft Magnetometer. In 1963 there were no low-power integrated circuits. His spacecraft magnetometer circuits successfully measured the magnetic field of the moon from orbit for several years.


Burwen Laboratories Modules MP202, UN201, and VU306. These epoxy potted modules were designed for use in the Burwen Laboratories model 10001. Some were incorporated in Mark Levinson’s famous LNP-2 Pre-Amplifier. Dick’s 20,000 watt sound system still uses more than 250 of these modules.


As a consultant Dick helped Mark Levinson with the first products of Mark Levinson Audio Systems and Cello LTD’s Audio Palette.


Mark Levinson’s Cello Ltd. product, the Audio Palette tone control system was a remarkable success and manufactured for many years. Dick submitted this schematic, description, and tentative specifications and features of a program equalizer to Cello Ltd. on March 3, 1984 and it became the basis of the Cello Audio Palette.


About 25% of the worlds hospital MRI systems used Dicks circuits. Copley Controls model 264 MRI gradient amplifiers.