[Phil Allison[_4_]]

Mike Rivers wrote:


Op amps almost never go bad by themselves. Something has to make them
fail. It could be a defective power supply regulator, or maybe a shorted
capacitor.



** Or like one Mackie 1624VLZ that came to me for repair with several dozen failed op-amps.

The user had connected the speaker output of a Marshall amp to one of the mic inputs - one that used diodes connected to each rail for protection.

The output from the Marshall was rectified by the diodes, driving the internal DC rails way above the usual +/- 16V.

The desk was a write off.

I saved the PSU and all the knobs.


..... Phil