One of my Tubes on the Jolida 301A flickers

You question is not clear to me? When you change the tube does the problem move with the tube? Example V1 flickers and is distorted and you move that tube to say the V5 position. Does the problem move to the V5 position or does the V1 position still have the problem?

Which tube is it? KT88, 12at7 or 12ax7? If it is only one position that causes the problem you have a few things you can do. Make sure the pins are all bent so they make connection and the tube is seated well. If that doesn't fix it you will need a tech.

It will be a simple problem. Not much to those amps. A couple resistors or a cap. Could even be a pinched wire touching the chassis. The power supply is shared by both channels so I don't think that is your problem. Anyway good luck.

The problem persists on the same socket when I swap tubes. I am using EL34's and they all seem to be doing the same thing when moved to V5 position.

Thank you for the response. Sorry it took so long to update.

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.

I'll check the bias tonight. Hopefully this will fix the issue.
Also, thanks for the information regarding a lower bias setting translates to more bass.

Thanks