Hi,
Mine is an AI L1 that uses 6922. Lately I realized the power supply section is running very hot. too hot to touch. I thought it was due to aging tubes but things didn't change even changing to a pair of new EH6922. Can anyone tell me what are the possible causes of transformer temperature to rise?
So far there is no blown fuse and the amp is still working even the PS section gets very hot but I'd stopped using it now to avoid causing further damages.
Please help guys. Thanks .
Mine is an AI L1 that uses 6922. Lately I realized the power supply section is running very hot. too hot to touch. I thought it was due to aging tubes but things didn't change even changing to a pair of new EH6922. Can anyone tell me what are the possible causes of transformer temperature to rise?
So far there is no blown fuse and the amp is still working even the PS section gets very hot but I'd stopped using it now to avoid causing further damages.
Please help guys. Thanks .
Not familiar with the product but i went looking for pictures.
Huh. I have those exact blue axial 0.01uf caps.
Anyway - my general guess is that maybe one of those heatsinked transistors has died in a bad way and is causing an overload in the power supply. It is interesting that it still works because a responsible designer would employ a fuse or circuit breaker to prevent excess current from damaging the device or causing a fire, etc.
If you have or can get a non-contact (infrared) thermometer you should be able to narrow down which parts are excessively hot.
But it may be advisable to seek authorized, professional repair service.
Huh. I have those exact blue axial 0.01uf caps.
Anyway - my general guess is that maybe one of those heatsinked transistors has died in a bad way and is causing an overload in the power supply. It is interesting that it still works because a responsible designer would employ a fuse or circuit breaker to prevent excess current from damaging the device or causing a fire, etc.
If you have or can get a non-contact (infrared) thermometer you should be able to narrow down which parts are excessively hot.
But it may be advisable to seek authorized, professional repair service.
If a regulator had failed there would be serious sound problems. To prove the transformer has not got shorted turns, disconnect the HT winding an insulate to make them safe, remove the valve and then run it. If the temperature increases with no load, replace the mains transformer. If you email your circuit to Majestic Transformers, Parkstone, Dorset, they may have the drawings still or at least make you a new one. Electrical Transformers Company, Poole, Dorset UK
It's does have cracking sound and sound of crumbling of PP polybag(you know what I mean?). One side is more obvious than the other.
I had the same over heating with my pete millett low mu preamp. Turned out the 6.3A supply was for 5a and all the tubes added up to 8a. I installed a separate heater transformer.
Ya there are two 14 pins 723. One on each channel.
and 712 with heatsink on each channel.
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How hot?
Hot!
How hot?
It the old days with work callused hands I could hold a hand on 140 degrees F for a short time with no ill effect. Today my lily whites are not so tough. 140 degrees is not so hot for a transformer, however too hot for my hand. I use a Fluke IR thermometer.
DT
Hot!
How hot?
It the old days with work callused hands I could hold a hand on 140 degrees F for a short time with no ill effect. Today my lily whites are not so tough. 140 degrees is not so hot for a transformer, however too hot for my hand. I use a Fluke IR thermometer.
DT
AndrewT
It is an eye brain perception thing to me. Arial jumps off the page more easily than veranda or other founts do.
My preference is a carryover from the engineering office where I worked. Arial was the official fount. I kicked up the size of the fount for the notes I would teach from.
We talk a lot of the perception of sound. Arial is a visual perception thing.
That is my story.
DT
It is an eye brain perception thing to me. Arial jumps off the page more easily than veranda or other founts do.
My preference is a carryover from the engineering office where I worked. Arial was the official fount. I kicked up the size of the fount for the notes I would teach from.
We talk a lot of the perception of sound. Arial is a visual perception thing.
That is my story.
DT
OK so when you disconnected the secondary windings from the transformer, ( HT B+ or whatever), what happens?
Does it stay cool?
Does it stay cool?
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