Case No. 6) Classe Audio CAV-75 Amplifier

A customer brought in a Classe Audio CAV-75 amplifier which was producing a "whistling" noise after the unit has been turned off.  The unit was previously back to the factory for repair.  According to Classe Audio the noise originated from capacitors which were not draining completely.  However, this did not fix the problem.

We diagnosed the problem to be originating from the Power Mosfet of the unit.  After we replaced some defective parts, and adjusted the idling current, results from out bench test show figures which exceeded factory specification.

The "whistling" noise was completely eliminated.

Estimated Repair Cost: $ 300.00       

Actual Repair Cost: $ 300.00

Turnaround time: 2 days.