In this system 1 of the 3 1250's has gone into protection on the last six channels on two of those channels we have two pairs of speakers they were originally wired in parallel and worked fine for several months now in protection we have changed them to series still have the problem. The strange thing is the speakers sound fine. No noticable difference when in protection. This is controlled by Audioaccess PX 700's and AA keypads.

Any insight on this problem would be greatly appreciated.

Have you whipped out your multimeter and checked the circuit yet?

Am I correct to summize that the Sonnance 1250 is a power amp. of 1.250 watts ?
Am I also correct to advice you to check every single speaker's impedance and make sure there isn't one or two speakers with an overheated coil causing this problem ? Unless some speakers on those two channels somehow got misswired.
Mister. T

Judging by the "last six channels" mention in the first post, I'd guess that it's a 12-channel amp of 50 watts each (1250).

It sounds like the amp's protection circuit is malfunctioning, registering a fault where none exists.

Larry
www.fineelectricco.com
My system

Larry I agree with you. I have checked the resistence on all the speakers and they are within the proper range. I will be calling tech support on Thursday just to talk with them.

Thank you all for your replys!

Billski, why don't you swith amp. with any of the other two and if it still goes in protection, then you know the problem is with the amp.
Mister. T

Beyond the usualy impedance checks---What are the switches on the back of the amp set to, for those chanels that do not work properly?

This amp has 6 separate stereo amps in it, and can be configured with switches to do several different things.

50 Watts per ch, x12 @ 8 ohms • 75 Watts per ch, x12 @ 4 ohms• 100 Watts per ch, x6 @ 8 ch, x12 @ 4 ohms• 100 Watts per ch, x6 @ 8 ohms bridged Dynamic Headroom: +1.9dB,

Configurable Input Signal Routing, Left/ Right/ Aux and Direct:Left Bus- Left channel(s) of theater
system, house audio distribution Center/Aux Bus- Center channel(s) of theater system, paging, tone signaling Right Bus- Right channel(s) of theater
system, house audio distribution Direct Input- Local audio or multi-room controllers Ability to combine any of the four bus signals together; makes simple mono
sound installations External control input - 6-24 volts AC/DC ground opto-isolated

I found the problem on the amp the connection to the sensor for the heat sink temp was slightly lose on the circut board pushed it down and everything appears to be fine.

Thanks everyone

Oh, one more thing....look at the heat-sink temperature sensor. Sometimes, the connection to the circuit board gets slightly loose. Just push it down, and everything will be fine.

Larry