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  3. 149918-77081

Tube amp troubles

Friends,

I am using an Ayon integrated tube amp. During a recent move, I had to take out all the tubes and when I put them back, I mixed up the low-power pre-amp tubes. I’m only mentioning this is as a context - I don’t think it has much to do with the actual problem I have. 

When I switch on the amp and start using it after some warm-up (the amp indicates when it’s ready for a load), everything works fine for about an hour. Then, the left channel goes totally mute. If I switch off the amp and let it rest for a few minutes (but not long enough to cool down entirely), it works again (after powering it back on) for a while - and then the same thing happens. The problem occurs regardless of the input, volume, etc. 

If you have any idea what this could be, that would be very helpful - I would like to avoid shipping this 48 kg beast to the only authorized dealer.

Also, if you know of anyone in the greater DC area who repairs tube amps, that may come handy, too, in case there is no quick remedy.

Thank you all,

Csaba
128x128malacka
malacka's avatar
malacka OP
8 posts
 
Ok, I switched the input tubes but the problem remained on the same side. So it’s not the input tubes’ fault. I will now try the output tubes (although they all have the same glow and similar temperatures).

I wonder what other component may react to the gradual build-up of heat with switching off one side of the amp. Also - and please do forgive the question - is there anything else that can accumulate during use in the components of a tube amp? Something that would only trigger, say a fuse, after 20-30 minutes?
noromance's avatar
noromance
9,769 posts
 
Sure there is. You could have a damaged passive component that is overheating or out of spec such that it is breaking down enough to trigger a protection circuit. You could open it up and do a visual inspection but it is unlikely you'll see anything. However, if you do not know what you are doing, it's best to have a pro look at it. 
kalali's avatar
kalali
1,977 posts
 
Take temperature measurements from the output transformers and see if they are close.  
malacka's avatar
malacka OP
8 posts
 
Thanks again. Last question:
do you know of any professionals (preferably within 100 miles from the greater Washington DC area) who could look at the amp?
bigkidz
3,381 posts
 
I am in New Jersey and can repair the amp.
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