Amp Shutting Down, need help

Switch mode supply??! I figured this thing had a big toroid...

Clearly the current limiting of the cord is having an effect.

So what is the outlet voltage while the amp and the cord are doing their thing? Bet it does not drop as much.

Based on that I would replace the AC receptacle, and make sure the screws on the receptacle are tight!

It would be a really good idea to see how this amp behaves in another apartment in the same building...

I do not think the amp is at fault if it really is SMPS powered.

Switch mode supply??! I figured this thing had a big toroid...

Hi Ralph,

Yes it has two big toroids.

Am I wrong in my thinking the amp could still have switch mode power supplies?

LOL, it wouldn't be the first time I have been wrong.....
Jim

"09-11-12: Atmasphere
Switch mode supply??! I figured this thing had a big toroid..."

They appear be two large toroids. If not, they would be the largest SM "inductors" I've ever seen for fairly moderate current demands of this nature, and I believe their distance and wire lengths would be of issue in a SMPS as well. If we could see what’s under the amp’s internal/central panel, I’d expect to see a bank of large electrolytics for a linear PS.

"So what is the outlet voltage while the amp and the cord are doing their thing? Bet it does not drop as much."

I can't recall if a measurement was taken at the outlet WITH the 50 Ft ext cord incorporated, but without it, the voltage dropped from 118 to 112 at the same outlet right when the mag breaker tripped.

"Based on that I would replace the AC receptacle, and make sure the screws on the receptacle are tight!

Note: The amp trips exactly the same way via 4 or 5 other outlet locations within his apartment per sailcappy.

"It would be a really good idea to see how this amp behaves in another apartment in the same building..."

I concur, as Jim and his EE friend has suggested, though not yet not tested by sailcappy. I recall Jim even suggesting he try to locate a service outlet outside or between apartments (if a cooperative neighbor wasn’t available).

Frank

If it has large toroids, there is no SMPS. A SWPS might look like an aluminum box inside the unit, but certainly would not sport any toroids, especially large ones.

So the theories around SMPS are not.

I still think its a good idea to try this amp in another place in the same building. Also, it would be a good idea to get the AC voltage readings from the wall when the amp is plugged directly into the wall, and also what the outlet voltage is when the amp energizes at the other end of the power cord. I'm thinking this might have to do with current inrush caused by an excessive dip in the line voltage at turn on, due to saturation in the core of the transformer caused by the dip itself when the transformer energizes.

If that is the case, it may be that replacing the outlet could sort it out....

If it has large toroids, there is no SMPS. A SWPS might look like an aluminum box inside the unit, but certainly would not sport any toroids, especially large ones.
09-13-12: Atmasphere

Ralph,

Thanks for the response. My limited understanding of SMPS was that a power transformer was not used. Then I got into a discussion with Jon Risch which I apparently got confused thinking SMPS could also be used with power a transformer.

I obviously misunderstood what Jon was trying to tell me.
My bad.... Thanks for setting me straight.

http://www.audioasylum.com/audio/tweaks/messages/18/184672.html

http://www.audioasylum.com/audio/tweaks/messages/18/184672.html

.
Jim