Anyone had and trouble with Jadis JP 80 amps

Hi, It should be a dark green 150R Resistor across the base of the tube
Just take bottom cover off and you'll see it--replace and test--though it sounds like a dicky tube, but I have replaced them and the units operate OK.

So give it ago it is easy to resolder plenty of empty real estate in their!

God Luck,
Des

Agree with Gmuffley about the high bias and tube failures. The old MO Valve and GEC KT88s lasted well in them, but every 6550 tube I tried started going bad within a year, and EL34s about the same. Too bad I didn't know about the trick with the resistors to lower the bias, might have saved me some money on retubing.

Thanks for the insight it been a real help