Epiphone Valve Senior Combo problem

[tuco ramirez]

Hello,
I purchased an out-of-warranty Epiphone Valve Senior from Musiciansfriend a few months back. It was a used special for about 200 bucks.

When it came to my workplace (had to hide it from the wife! , I turned it on, plugged in and literally strummed a chord to make sure it was working. And i was satisfied with that. That was my mistake.

To make a long story short, I finally took it home, and played it , and discovered that the amp just dies after about 5-6 minutes of playing. And consistently too. I changed the tubes, made sure the original tubes worked, and its definitely not the tubes.

In another forum, I found a user who had a faulty Epi valve Senior, but I could not determine if his/her amp was displaying the same symptons. this is what they wrote:

I've just repaired a faulty Valve Senior and the output stage cathode resistor was far too small in my opinion. Meaning that the 6V6GTs in the output stage were running VERY hot indeed - one had died as a result. I've swapped the "stock" 250R 10W resistor with a 680R which placed the output tubes in their safe operating region. I changed the undersized bypass cap to a 47uF 100V (the old cap had exploded!).

I also added additional 470k grid resistors to the output stage to maintain grid bias in the event of the cheap-quality master volume pot developing an open circuit. Also, added an inline internal HT fuse.

So, my question is, would the above rectify my issue? Or do I simply have to take it to a tech? Or is it something I may be over-looking which i havent tested? (the amp has a tube driven reverb) . I should add I reached out to Gibson, but they are not able to take it back and repair when out of warranty.

I am pretty handy with a soldering iron, so any suggestions would be welcome. Im ready to rip the mofo apart!

[tuco ramirez]

bump ? any ideas anyone?

thanks