Wilson...I looked up "tctubes.com" and now I see why you asked, and I hope you find out and let me know. Although I will feel bad that MY tubes weren't as "custom matched"...damn! |
I guess the answer is no. |
Pretty much every KT120 sales spec/note/description including the "official" one from New Sensor has that "tube heater current filament supply or" warning. I stand warned. Audio Research along with a bunch of other amp builders have modified their transformers to handle this issue and I still had to ask...is there a melted amp someplace? I bias the KT120s to the Jolida 500mv specs (I use a voltmeter even though the Jolida "ez bias" LED thing works fine) and the KT120s sound significantly stronger in every way over the otherwise fine stock (also Tung Sol) 6550s. I even talked to Kevin Deal at Upscale Audio and he said the KT120s are selling like hotcakes and he's never heard a customer mention an actual transformer overload issue...so much for my little research project.
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Luckily there seem to be NO transformer issues with the 502P. Not yet anyway, and I assume if it was gonna die it would show some signs of impending failure. My trusty warranty is there just in case. The CJ "SE" is on a price level that begs comparison to "things that interest me" like the Cary 120SII, Audio Research VS 115 (now with 8 KT120s!) McIntosh MC275, and other stuff, but the Jolida sounds so damn good and provides me with the requisite space heater and tube glow features that apparently I now need, so I'm content with it. At around a grand new there's not a lot out there that compares. |
There's just nothing wrong with robust filament winding. I'm all for it. |
According to my research (kinda lame...consists of merely asking on these forums and talking to some "tube head" designers and "experts") there has never been a transformer failure in any amp in the history of the world from using KT120s. The entire world...all of it. That's what my research has shown to this date. |
The Roswell crash proves that interstellar space aliens should NOT be using Russian tubes (back then from OUR future no less) without robust transformer filament windings.
I have no idea what "Smoffat" is, or what a CL-120 is unless you mean the old ARC amp.
I had a 1971 Honda CL450 for years, but that was a double overhead cam "street scrambler" motorcycle...should have kept it. No tubes, except for the tubular frame and shocks. |
Damn...that's such sad new for CL-120 users everywhere. I hope they can go on somehow to find meaning in this otherwise tube specific world we share as they stand in the cold shadows with their frostbitten noses pressed against the window hopelessly watching others who in fact can, and do, use KT120s. |
Nope...but you should feel free to call them and bet they'll give you the info you want. I merely described to them the "filament headroom" warnings that I kept noticing in the KT120 descriptions and they said there's plenty of transformer headroom built in. I've been using KT120s for a few weeks now and they sound great with no issues, although I have no idea what the "issues" might be (melting? radioactive waste?). I'm using 2 factory "matched" pairs...otherwise nothing special about them. |
I wondered the same thing, but went with a standard factory matched quad without "cryo" treatment just to be cheaper...and now I'll never know! Supposedly the fact that you bias each tube individually makes it less important to have them so carefully matched (according to the manual), but I'm no expert. I did read more about the "cryo" treatment later though and it seems interesting. My amp is still sounding fine, and better actually...KT120 tube break in? Maybe get a custom matched set of KT120s and send 'em out for cryo treatment someplace...your local college science lab might do it for free! |
A rhetorical question I deem unanswerable. I am the "deemer". |
Jedinite24...did you stick the KT120s in yet? Mine keep getting better...not sure if they've peaked yet, but they likely have. Also, I discovered that some new tubes have a "new tube burning smell" that I thought might be the Jolida frying until I tried some new KT88s that had a "burning glass" sort of smell for a day or 2...just like the KT120s. |
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. |
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. |
