The custom-built testing machines at FM ACOUSTICS meet every possible demand. Besides standard tests such as distortion analyses, noise measurements frequency response etc. other special tests and measurements performed by these machines include the following:
* A wide variety of switch-selectable loads
* Accurate voltage and current measurements
* High voltage insulation tests
* Wave from tests
* phase linearity tests
* Attenuation accuracy tests
* Thermal tracking and operation measurements
* Thermal overload tests
* Multiple specific error generation for checks of protection circuitry
* D.C. offset tests and calibration
* Ultra-accurate CMRR measurements
* Transient behaviour tests
* Multiple burst measurements
* Short-circuit tests
* Precision RIAA and de-emphasis
* Precision filter measurements
* And more...
After each product has been pre-tested and performs perfectly, and after all data have been recorded, the unit is then moved to the specially built burn-in room. There it is exposed to a
long-term burn-in test running under the most severe test conditions, this for at least 200 hours in a thermal multi-cycling mode.
These cycles are programmable from a few minutes up to several hours. The units consequently heat up and cool down repeatedly, going through between 1000 to 2000 full thermal cycles. In this manner worst-case test scenarios and heavy-duty burn-in (including the important pre-aging) are achieved and the possibility of later malfunctions and defects is virtually eliminated.
The above picture shows FM 111's and a studio amplifier on the burn-in rack.