Genius2!: David Hafler and the DH-200 #271 February 2017
The achievement of simplicity is as much a signifier of brilliance the complicated and esoteric. David Hafler became known for his practical applications of high-end technology in accessible packages. After coming to prominence with hi-fi amplifiers, particularly in kit form, he became a pioneer of MOSFET amplification in the pro sector and proposed a system for surround sound based on only three loudspeakers.
Born in 1919, Hafler graduated in mathematics from the University of Pennsylvania. He founded his first company, Acrosound, in 1950 with business partner Herbert Keroes, producing transformers for tube amplifiers and ultra-linear output stages for amps.
Hafler formed a new company, Dynaco, in 1954. This produced the Dynakit self-build power amps and pre-amps that became popular with hi-fi buffs during the 1950s and ’60s. He sold Dynaco to Tyco in 1968 and after a period as an advisor set up the David Hafler Co in 1977. This also produced kit amps but offered ready-made models as well. These included the DH-101, DH-110 and the DH-200, which had MOSFET outputs, regarded as ahead of other amps of the time.
Leaving hi-fi behind in 1995, Hafler concentrated on power amps for installation and studio applications. Peter Janis, chief executive of Radial Engineering, which now owns the Hafler brand name, says the man himself “was always trying to figure out the shortest path to successful sound”.
The idea of eliminating parts for a simple design can be seen in Hafler’s proposition for surround sound from the early ’70s. His three-channel system used the difference signal of standard stereo to produce a rear-speaker feed. Unlike quad, this did not need special recordings or playback techniques.
David Hafler died in 2003 but his name – and genius for cutting through technology to produce good sound – lives on in amps for the professional and home theatre markets.
Published earlier this year and sponsored by QSC Audio, Genius!2 is the second edition of Genius!, celebrating those clever people whose inventions have transformed the world of professional audio. The 30-page supplement is also available to read in a handy digital-edition form