On Sunday July 12 2009 2PM while listening to my home main audio system at well below 100dB it popped hell for loud and all the amp fault lights came on. I powered it down as fast as possible. Then I could hear my air compressor in the garage give four or five locked rotor growls and quit by the time I got to it.

My stereo is on its own 40 amp 220V circuit with a Furman ASD120 power sequencer with a 20A circuit breaker on each switched outlet and a MOV on each from line to neutral. Not one tripped breaker or burned MOV.

The stereo is 5 way dual mono with a Sony ES1000 preamp feeding a left and right DBX 260. Each 260 drives a Crown CE1000 driving the 2404's and the 2426/2344's.
A CE2000 drives the 2123's and E130's.
A CE4000 bridged drives a GTI1800

The 1000's survived, everything connected to them did not.

The 2000's are dead, other than one 2123 that had the voice coil pushed out of the gap ( that I got back in and its fine!!! What are the odds? ) those drivers lived.

The 4000's and 1800's are fine, as are the 260's and preamp. The Sony will power off when ever it see's anything it does not like power wise and you must interrupt its power and restart it or it wont come back on. It did not power it's self down on this event.

The compressor is an industrial unit with an "if then board" for faults like out of oil or the air filter fell off and a triac instead of a mechanical relay on the motor. It is sensative to high frequency. If I forget and leave the work ground wire to the TIG welder neatly coiled under the TIG and step on the pedal to weld, when the high frequency generator starts to initiate the arc the compressor will freak out as the triac cycles very rapidly and beats on the motor.

In all of this, this is the only clue as to what might have rode in and wrecked all my stuff. The compressor is undamaged.

You have to try to find something so I have pulled and checked the connections on the outlet in the room, the wires on the breaker, the mains to the buss bars, tripped the breaker manually ( not frozen or welded ) and set up my Fluke to record the voltage difference between safety ground and neutral for a 24 hour period with a max reading of 3.7V wich I thought was plenty low.

The transformer for my house is right across the street from me, is underground wired in by a single 15KV wire and out to us. No one else on my block experienced an event. Seriously what the hell?!?

The power company is coming this week to "prove" the connections from the transformer to the house. I bet they are OK however.

We have talked about whole house protection systems for spikes and surges but I am not sure either of those types of faults occurred.

Any educated ideas? Im all out.

Oh by the way, if anyone is really searching for the "Brown Note", here is a hint, it may not be a note, its probably an impulse.