Tube upgrades for Jolida 502B?

I've bought a majority of my tubes used or already burned in from the seller so it has been plug in, play and enjoy. From reading in other forums about 100 hours will do for your tubes to break-in. Enjoy. You've got quite a batch of tubes there for your Jolida. I have the Mullard CV4024 in my Jolida amp as well. The only tubes I've been swapping are the 12AX7s.

Or the audio grinch who incited incendiary hifi jinks and stole playback of Mannheim steamroller the world over. Hey legacies are hard to come by in this 5 milliseconds of fame world. Happy New Year everyone, at least the solid state folks will just say...wha?

Risking redundancy I offer the following: My Jolida 502p is currently sporting "matched" KT120s, "Preferred" tubestore 7025s (a Chinese version in the 12AX7 family that really sound great), and tubestore sourced NOS JAN Philips 12AT7s that I just installed...the JAN Philips seem to sound a little more refined than the stock EH 12AT7s, and they have the benefit of having more exposed glowing bits and that's always a wonderful thing regardless of sound quality. "We roll because we can", Wolf Garcia 2013.

question about kt120 tubes. i spoke to walter from underwoodwall the other day and asked if i can use 120 tubes in my 502p amp. he said no. i dident ask why but i see other folks here using them. so, whats the story?? is it safe to use kt 120 in this amp. and if yes, do you still bias so the led,s go on??. i understand they use more current or something so wondering if the 502p power supply stiff enough for them. thanks

It has to do with the current supplied from the transformer for the tube "heater" or "filament" elements in the 120s...100mA to 300mA more than KT88s. Walter is simply wrong about this, and based on all the discussion about it in this forum, I'm surprised about that. I bought a 502p a year or so ago and upon getting the approval of the guys at Jolida MD (they said the amp can easily handle the extra current), I took the bold and dangerous step of sticking KT120s in my amp. Yes, I'm clearly a courageous risk taker, but that's how I roll (tube roll anyway). In any case, myself and other courageous risk takers have been using 120s in these amps for a while (in my case almost a year) with zero issues. As part of my ever dilligent KT120 amp explosion death watch campaign, I have yet to hear of ANY amp melting down from using 120s...but I shall continue to my vigilence on behalf of my fellow 120 users, because, clearly, I'm a giver.