MC501 Thermal Shutdown

[Vintage Pete]

Originally Posted by two dot

501's with LOTS of air space around them.

I thought you were usinng 501's. Your amps were shutting down?

Pete

[Still-One]

Dan
Do you still have your PPP's sitting on top of the 501's.
Jim

[jdandy]

Pete.......I was surprised myself, but the only method these amps have to cool themselves and maintain safe operating temperatures is convection. I knew when I measured the Salamander Twin 40 for the gear that it would be close quarters for the amps. The front of the 501's consume almost the entire opening, with 5/8" space from the top of the amp's glass to the bottom of the shelf above, and 1" clearance on each side. That's not much room for a healthy amount of static air to be drawn in or escape by convection. The back of the rack is open, but less than 5" to the wall and crowded with power cables and interconnects.

I have not had any cooling problems with the MC501's when they were installed in the single oak cabinet, but it was wider, with more space on each side of the amps, and more space above the amps on each shelf. On more than one occasion I played music at the full 500 watts output on peaks with no sign of overheating in the oak cabinet. Like you said about your amps, the heat sinks got hot, but not blistering hot under those conditions. Had only one of my amps gone into thermal protection I might suspect some other problem, but they both reacted simultaneously within seconds of each other to the same heat conditions. More air flow in the Salamander cabinet will remedy this issue.

[jdandy]

Originally Posted by Still-One

Dan
Do you still have your PPP's sitting on top of the 501's.
Jim

Jim.......No, the Power Plant Premier's each have a separate shelf above the 501's. They are not running any warmer than they did in the other cabinet sitting directly on the 501 amplifiers.

[PHC1]

Dan, I would run two experiments in the mean time.

1. Take the 501s out of the racks and play the same track at the same volume with the amps being out on the floor with plenty of air and space around them.

2. If the thermal shutdown occurs with above, take the MEN220 out and repeat....


With peaks of only 200w on amps rated at 500w sitting inside a standard stereo rack is not something that would be considered normal....

[Still-One]

Dan
How was your power today. Could low voltage due to high demand have made it difficult for the PPP's to provide sufficient power ie corrected to 120v.
Jim

[vintage_tube]

Originally Posted by PHC1

Dan, I would run two experiments in the mean time.

1. Take the 501s out of the racks and play the same track at the same volume with the amps being out on the floor with plenty of air and space around them.

2. If the thermal shutdown occurs with above, take the MEN220 out and repeat....


With peaks of only 200w on amps rated at 500w sitting inside a standard stereo rack is not something that would be considered normal....

Easier said than done though; but, a great suggestion Serge.
Bob

[jdandy]

Originally Posted by PHC1

Dan, I would run two experiments in the mean time.

1. Take the 501s out of the racks and play the same track at the same volume with the amps being out on the floor with plenty of air and space around them.

2. If the thermal shutdown occurs with above, take the MEN220 out and repeat....


With peaks of only 200w on amps rated at 500w sitting inside a standard stereo rack is not something that would be considered normal....

Serge.......Thanks for the suggestion. I have company coming tomorrow, so not likely to have time for that experiment until Thursday.

[80B]

Dan,
Were you surprised by the shutdown? Did you ever notice much heat before - either pre-or post- rack change? I do hope the fans fix the issue for you.

Your observation about them both shutting down nearly simultaneously being a testament to their engineering is absolutely true.

[vintage_tube]

If you have the MC501's triggered -- and the 1st triggered amp went into shutdown, wouldn't that cause the other to shut down seconds afterwards.(??).

Bob