The Dynaco Stereo 80 (or ST-80) is an awesome compact amplifier. It's got the power of solid-state with the looks of a tube amp. Looks cool, sounds even cooler.
- Full service check
- Cleaned controls, switches, and chassis
- Replaced defective power supply capacitors
- Replaced defective output capacitors
Power output 40 watts per channel into 8Ω (stereo)
Frequency response 10Hz to 50kHz
Total harmonic distortion 0.5%
Damping factor 40
Input sensitivity 1.3V
Signal to noise ratio 90dB
Speaker load impedance 4Ω to 16Ω
Semiconductors 12 x transistors, 10 x diodes
Dimensions 14 x 8 x 4 inches
The History of Dynaco
Founded by hi-fi pioneer David Hafler and Ed Laurent in 1955, a small company by the name of Dynaco unknowingly would become the most popular tube amplifier company of all time. Five years prior in 1950, David Hafler and his friend Herb Keroes started up the company Acrosound, dedicated to building audio quality...
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The Dynaco Stereo 80 is an all silicon transistor basic power amplifier for use with separate preamplifiers such as the Dynaco PAT-4 or PAT-5 or for use with tape recorders or tuners such as the Dynaco FM-5 which have their own volume controls. The unit contains two 40 watt amplifiers on one chassis with a common power supply. It has been designed to be used under normal conditions without special safety precautions, just as if it were a high-grade tube amplifier. There are no circuit breakers, speaker fuses, or other resettable devices to impede the use of the Stereo 80 under any reasonable conditions of use or abuse. This is achieved by using novel circuits (on which patents are pending) which automatically and instantly protect the amplifier. The components are of the highest quality to protect against failure, both now and for many years in the future. All parts are used conservatively with close tolerances to assure proper operation, and etched circuit modules are pretested under actual use conditions to ensure that every unit, after assembly, will meet the specifications normally associated with laboratory prototypes. The specifications of the Stereo 80 speak for themselves. The distortion at low levels is comparable to that of the finest tube designs, while the high power distortion remains inaudible.
Specifications do not reveal all the facets of sound quality, however. In use with varying program material, the unit justifies its design efforts to have qualities of ease and naturalness always sought and rarely achieved in solid-state designs. There is no extra brightness or stridency which is unfortunately sometimes attributed to high fidelity sound, but rather there is an impression of limitless range and effortless handling of the highest power peaks.