Ideal EL84 tubes for a balanced tone and smooth overdrive in a JMI era AC30 TB with 50r cathode resistor?

[VintageCharlie]

Oh, I should have mentioned that I also run an Albion OT, but one made by MM 20 years ago, so not original. It's a very nice OT and takes a beating quite well. They say the real deal Vox trannies were potted not in lacquer but some sort of beeswax concoction that, once the amp got super hot the paper bobbin and the beeswax would light on fire. (I will assume there was a power tube short in there somewhere that arc'd the OT winding.) I think it's Gerald Weber who presents this Vox beeswax OT fire somewhere in print, look around. He is possibly a conman on some level, true, but even so it is a good story. And yep, I remember quite fondly the time I was playing a gig (when I was 14) and the 6/10 four 6L6 piggy back Silvertone burnt up one of it's OTs. No flame, just a very solid stream of thick smelly black smoke rising to the gym ceiling. It happens.

But a good AC30 roars like a lion when it's right so maybe a little fire and flame should come with it, eh? Good luck with you amp.

The stories about JMI AC30 unreliability are interesting. There are often people who will quickly jump into these threads and dispute any claims of the unreliability and others who will tell stories how they survived unimaginable torture. E.g. leaving amp accidentally on for 2 weeks, finding it having warmed up so much that the beeswax is dripping out, but still sounding and working great. My personal experience is they work great despite the heat. My issue with them is that they use cc resistors, which are 20% upwards at minimum and often 50% or 60%. That makes tremolo circuit trouble-shooting fun and the hot operating temperatures just speed up the degradation of these resistors. Just an example - i found the 100r resistors at the output tubes in one of the amps i owned to read about 160r - all 4 of them. So it seems very directly heat-related.

[Roe]

I'm running one pair of 6p14s and another pair of cheap chinese el34s. the former sound darker, the latter chimier. the combo is nice

[Zouto]

I use NOS 6P14P-EBs in several Vintage AC30s for a warm and chimey sound and great reliability. It‘s important to select good quartets.