PRIMA LUNA DIALOGUE PREMIUM - 20 minutes and then loud pop and buzzing in 1 channel


Hopefully someone can help.

Amp is virtually new. The amp will operate wonderfully for 20 minutes and then a loud pop , and then buzzing from the right channel. I shut down the amp and then it repeats.  I switched some tubes and it is still there.  I switched the cables and know for sure it is only one channel, the right one. The buzzing does not increase with the volume increased. . 
It is the amp and not the Prima luna preamp.  Cables and connections are fine.   Pushing Focal Kanta No2's . 

Any help would be very much appreciated. I'd rather not send a 68 pound piece of equipment through the mail. 

Thanks lot - Craig 

128x128vespacraig1966

Showing 1 response by millercarbon

Sorry to hear. Especially since Prima Luna is on my very short list of amps if I were to replace or upgrade mine. You've made all the right moves to narrow it down to something internal, like caps or transformers or wiring. The 20 minutes makes me think thermal. But if you turn it off and right back on again (no cool-down) and it still goes for 20 minutes wow, you got a mystery there. 

I've shipped enough of this stuff to no longer worry about the component. What I worry about now is the box! Cardboard gets beat up. 

Get yourself the Costco rolls of packing tape. Fold cardboard into angles and tape them to reinforce all the edges and corners. Then cut another box to fit snug and tape the you know what out of that. So a box to protect the box.

Print FRAGILE GLASS and laminate that to every side. Then call around, or ask your shipper, to stick shock sensors (liquid filled tube breaks if hit too hard) on it.