Trace Elliot AH250 - Starts to spark after 30min

[überfuzz]

I've just laid my hands on a Trace Elliot AH250. It's seems to be doing quite ok at first. But at half a hour it start to spark.

If there's anyone here that have experienced this behavior or that have repaired a Trace Elliot with this... condition I would really appreciate some tips on where to look for gnarlys.

[Steve Conner]

Where do the sparks come from?

[überfuzz]

Oh... Sorry for my imaginative way of describing the noise. There are no sparks flying. The amp starts to pop and make sparking noises after some 20 - 30 minutes.

I think I'm going to gut it and see if the filter caps are bad. The thing is, I really don't have any experience tinkering with solid state amplifiers. That is way I posted this thread.

Cheers!

[Steve Conner]

I've seen bad transistors cause funny noises like this. They were little TO-92 ones, part of the driver circuit in a MOSFET hi-fi amp. They ran very hot by design, and eventually started to degrade.

But it could also be a bad resistor or cap. Not likely to be the large filter caps though: if those were bad, the amp would hum and sound rough and distorted. It wouldn't cause popcorn noises.

[Enzo]

Isolate the problem. Does it still make noise whith ALL controls at zero?

ANY control that has ANY effect on the sparking sound is after the source of the sound.