KT120 transformer failures

Hey Wolf
I got the KT-120s but my 502p is @ my local Jolida dealer getting upgraded. The guy is a tube expert so I trust him with modding the amp. In another couple of weeks I'll be able to enjoy the music as well as the buring smell you mention from the Jolida & the KT-120s. Thanks for the heads up on the buring smell. I probably would have been worrying about that. Which KT-88s did you try? I have my eye on the Penta KT-88SC tubes just in case if the KT-120s don't work out. Also when I spoke to the dealer/tech he said the Jolida 502p could handle the KT-120s w/ no problem. I can't wait to get up & running w/ everything.

My KT88s were an impulse purchase at a local "DIY" place and they're sets of "matched pair" Svetlanas...I think Svetlana has an OK reputation and in any case they weren't expensive (same Russian factory also). I think the KT120s have a little more clarity or something...bigger sound sort of, but the 88s do sound good (as do the 6550s). I guess I'm good for YEARS of power tubes now. Good luck with the mods, and it feels good that another Jolida tech thinks the 120s are OK as that was a hard issue to nail down. It's interesting how the 502 just keeps impressing me, and now I suppose I'll be looking at 12ax7/at7 rolling...it's endless and like it!

Correction: SOVTEK kt88s, NOT Svetlana. I miss-Russianed.

Sovtek had made a decent living producing the worst sounding tubes in the industry. The surprise would be if you didn't find you're happier now with something else.

A lot of OEMs, who keep the brand in business, use Sovtek because of the pricing and their general reliability. Of course, these are not the worst as they are a KT88 - 6550s beat them in that regard.

Interesting post there Trelja...My Sovtek "brand" kt88s are produced at the same New Sensor factory as my sets of Tung Sol 6550s and kt120s, and they (the kt88s) sound GREAT...upon close physical inspection using my watery and often reddened eyeballs they do seem to have very similar "innards" to the 6550s, but sound and behave differently nonetheless, as well they should. I find it hard to imagine why a factory would make a poorly regarded tube when it also makes very highly regarded tubes (they're the ONLY ones making the universally accepted kt120s) in the same place. From the Tube Store:

From our KT88 tube type listening tests:
"The Sovtek KT88 tube has smooth, warm and clear with excellent imaging. The bass (except for the very bottom end) is tight and the high end is crystal clear. The separation of parts and balance is better than any of the 6550 tube types."

They left out (assumed typo) what IS "smooth, warm and clear"...the glass? The sales staff? The skin on the factory manager's mistress? Mine don't run with "red plates" or explode...although they do have a beautiful blue glow that appears after a while. Also, I just googled 'em and they seem to be more or less accepted by "geekdom". All this aside, for reasons I find hard to explain I am currently preferring the kt120s...if only because they're larger and seemed to become depressed when I put them in their little boxes to try other stuff. The sets of 6550s and kt88s are in a large box together so they can discuss their early days spent on the Volga. I will not let them near any vodka.