Dynaco: Американдық аудио өнімдерінің тарихы

Founded by David Hafler and Ed Laurent in Philadelphia, Pennsylvania in 1955, Dynaco was an American hi fi audio system manufacturer popular in the 1960s and 1970s for its wide range of affordable, yet high quality audio components Its best known product was the ST 70 tube stereo amplifier. They also manufactured other tube and solid state amplifiers, preamplifiers, radio tuners and bookshelf loudspeakers. Dynaco was liquidated in 1980, and the trademark is now owned by Radial Engineering Ltd.

In 1950 David Hafler and Herb Keroes started a Philadelphia based company called Acrosound to build and sell audio quality output transformers, primarily for home electronics hobbyists. A modified aperiodic bass reflex design using SEAS speakers in a handsome wood cabinet, the A 25 sold for $79.95 each in 1969 making it competitive with much more expensive loudspeakers. The patented aperiodic (essentially non resonant) woofer design utilized a highly damped vent instead of a reflex port, whose acoustic resistance is very carefully controlled. The resistant venting action lowered the "Q" of the system and reduced impedance variation near resonance in the A Series speakers. Dynaco followed the A 25 with the slightly larger A 35, which featured a dual chambered, non vented design in a walnut veneered cabinet with even greater transparency and fidelity. Over time, Dynaco marketed a wide range of loudspeakers, ranging from the small A 10 model to the floor standing A 50 series. After some 30 years, these loudspeakers still command good prices in markets such as eBay, and are a testimonial to their quality. Concurrent with A 25 production, Dynaco introduced the QD 1 speaker adapter which synthesized 4 channel sound from the stereo amplifier output. This "Dynaco patent" required a single resistor and a threeway potentiometer for the two rear speakers, generating phase difference signals for a feeling of ambience. The system worked best when the stereo sound had been recorded via two bidirectional microphones on the same spot. When microphone set up changed to the use of multiple directional microphones and multitrack tape recording and postprocessing (i. c. in the CD era), the QD 1 was less effective. Dynaco became a wholly owned subsidiary of Tyco, Inc. in 1969. David Hafler remained with the company a few years longer, but left in 1974 to join Ortofon, manufacturer and importer of high end phono cartridges. In 1977, Hafler founded the Hafler Company, continuing the tradition of high quality but inexpensive kits and assembled hi fi gear. In the late 1970s, Dynaco released a short lived set of new loudspeakers developed by Ed Laurent, the Phase III. The speakers were well regarded by the audiophile community, but their introduction was apparently too late to make any strong impression in the marketplace, and Ed Laurent left shortly afterward to join SEAS Corporation. After Dynaco closed its USA operations, its former Canadian subsidiary released the Dynaco A 150, A 250, and A 350 speakers, all manufactured in Canton, Massachusetts. Critical reviews of the new audio speakers were not favorable, and they disappeared from the market in the mid 1980s.

Dynaco was acquired by ESS Labs, LLC in 1979; the Dynaco division was closed in 1980 and its assets acquired by Stereo Cost Cutters (later called Sound Values and Sound Valves). In 1991 the Pan Orient Corporation (later Panor Corporation) acquired the Dynaco trademark, and in 1993 began marketing electronic audio components with the Dynaco brand. Panor introduced some new products, such as the Stereo 70 II. Panor/Dynaco's most ambitious stereo tube amplifier was the Stereo 160, a 75 wpc, all tube stereo power amplifier with switchable pentode/triode modes, adjustable tube bias potentiometers, and 6550 output tubes. While Panor owns the Dynaco brand name and trademark, there is no longer any direct connection with the company founded by David Hafler.

Dynaco introduced tube audio amplifiers, tuners, and preamplifiers between 1955 and 1976. Model Type Channels(Power) Year Introduced Dynaco Mark II Power Amp Mono(50 watts) 1955 Dynaco PAM 1 Preamp Mono 1957 Dynaco Mark III Power Amp Mono(60 watts) 1957 Dynaco Stereo 70 Power Amp Stereo(35 wpc) 1959 Dynaco PAS 2 Preamp Stereo 1960 Dynaco Mark IV Power Amp Mono(40 watts) 1960 Dynaco FM 1 FM tuner Mono 1961 Dynaco Stereo 35 Power Amp Stereo(17.5 wpc) 1963 Dynaco SCA 35 Integrated Amp Stereo(17.5 wpc) 1964 Dynaco FM 3 FM tuner Stereo 1964 Dynaco PAS 3X Preamp Stereo 1966 Dynaco Mark VI Power Amp Mono(120 watts) 1976