I was using external power OctavianH, sorry should have mentioned.

I've used KT88 as drivers but found I lost too much gain. Now using Valvo EL11 which is a very good driver with 5998's and gives me plenty of gain.

I'm with you there, still using T1 with Euforia and RME ADI 2 FS dac and on occasion with Benchmark HPA4 with Hugo TT1 (for classical). Still loving it. Also own T1 gen 2.

It's not really possible to say whether they are nos or not by state of pins or print, it all depends how they have been stored. Personally I would be looking for original boxed tubes before considering if I was only interested in nos tubes. Sorry not much help. Providing there is the...

Look good to me. Enjoy.

Hi. Have you tried completely down powering amp and leavening so for a couple of hours. I had a similar issue many moons ago and that did the trick Best of luck

Not quite unobtainable UT. I managed to come by both Telfunken and Valvo mesh plates. Valvo's dating from 1939. Needless to say both are keepers

I'm still using one of your earlier favorite combinations 5998's with Valvo EL11's as drivers on my Elise. Still sounding great. In Euforia it's H1's very last combination, also a great pairing.

I have Elise mk1 along with Euforia mk1 and at times with certain tube combinations the Elise is my preferred listen. I'm sure there is very little difference audio wise between mk1 and 2.

Possibly a faulty adapter. Doubt you have a spare so you could try using two different driver tubes without adapters then change all power adapters so as to test all four. It is not unheard of for KT88/KT66 to have a slight hum which is usually lost when music plays. Good luck. I run EL11'S into...

I bought mine from a seller on head-fi when it was just about six years old. I got new batteries fitted to be on the safe side and have never looked back. Really excellent piece of kit. No signs of any problems and I'm sure it sounds just as good if not better than when it came off the factory...

I've owned both Elise and Euforia for over 4 years and have rarely used stock tubes in either. Had no issues what so ever. I bought both my amps secondhand so loosing warranty was never an issue. At present the tubes I'm using in both amps are KT66 and KT88's (Euforia also 2 xGU50's with...

Hope you feel better soon H1.👋

600 or 300 ohm's?