Check your bias! I bet the bias is off. What you mention about the tube flickering and distortion is what happens when you install new different final output tubes. get a digital multimeter, a small flat head insulated screwdriver and adust the bias to -.0040v per tube. From my experience if you want a little more base you can run the tubes a little cooler, like -.0035v If you run too cold you will loose the crisp midrange and highs. too low and you get the results you described, too high and your tubes will glow brightly and live a short life. You need to check your bias every 2 years and whenever you replace the final output tubes.
One of my Tubes on the Jolida 301A flickers
I was playing an LP today and noticed that each time a low frequency measure was being played, the sound was distorted. I played the same measure over again several times and confirmed the existence of distortion not previously heard. I watched the tubes while tracking through this measure and noticed that one of them was getting brighter. Thinking that maybe a tube is ready to go, I swapped it out for the adjacent one to determine if this is a tube issue. The same thing happened with the swapped tube. I tried another tube and again the same thing happened.
Has anyone had the same happen to their amp? Can you share what the root cause was?
Thanks in advance.
Has anyone had the same happen to their amp? Can you share what the root cause was?
Thanks in advance.
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- 10 posts total
- 10 posts total