Need Advice for Different Power Tubes in 2525H Mini Jubilee

[DaMose]

Was looking for some advice and suggestions on power tubes for my 2525H. First off I’m not certain what I’m asking is even possible to do safely for the amp and the transformers. Keeping that in mind with the amps ability to self bias I was mainly interested in knowing what I can try in the way of different power tubes safely in the amp? I would love to hear reports from other users that have already ventured into this area. Obviously I know the KT77 is fine to use but wondering about what other power tubes can possibly be used and can it be done? 6L6GC 5881 KT66???
If that dream of rolling different vintage power tubes in the 2525H is dead on arrival then my next question would be what are some of the users favorites that are using vintage old glass? I’ve got a pretty good selection of stuff here from more affordable RFT vintage tubes all the way up to pricey Mullard and Amperex tubes in matched pairs I could potentially try but I’m mostly wanting some ideas of where to start from others and not just starting to throw everything I own in there one at a time. I found you tend to go “ear blind” with that approach. At least for me.
Next question is what do you fine folks tend to like the most in the new production EL34’s out there? Mullards? JJ’s? Does one brand seem to shine above the others in Marshalls in general or particularly in the Jubilee?
Anyway I know I’ve asked a lot here but any guidance would be much appreciated

 

[DaMose]

 

[MaskingApathy]

Yeah you can use any of those power tubes in it. I like the JJ E34L personally.

 

[scozz]

I’ve been hearing a lot of good things those E34L that @MaskingApathy suggested, I’ve never tried one though.

I might get a pair to try in my SC.

 

[Jethro Rocker]

I put a pair of 88s in my SC20. Ballsy!! Yes they work at that lower voltage.
Brand and type sadly is subjective. Trial and error gets expensive.

 

[XTRXTR]

Drake OT 784-139?
Drake PT 1202-324?

If yes then anything on that list you want as long you can adjust bias to levels for each tube.
My Marshall 2550 and my JCM 800 2204 have that iron and I made the bias adjust to 6550, KT88, EL34, 6L6xx, 5881, Never tried KT66 only because I love the 5881 and EL34. Anyway no issues for me.

 

[DonP]

My used 2525H came with a pair of Tung Sol EL34B's. One was dead.

I swapped in a pair of EH 6CA7's. No issues, plenty of bottom end.