I am only referring to my own experience as a tech, and although big fan of winged 'c' (not the U.S. Svetlana's), I am not trying to sell anything or put sovtek out of business, but many MusicMen passing through me have had problems because of tube failure.
I'm sorry if it came off that way. That wasn't what I meant. I had no idea of your location, so that in itself is a huge qualifier as to our differing views. Svetlana had a separate Northeastern Europe distributor with a Russian contact at the factory that got better tubes than what was available in the US. I tried to order from them a few times, but they never replied to any of my inquires. They had a couple of models that were even completely unavailable at all in the US like the Svetlana EL509 II, which I would LOVE to get ahold of. "Svetlana," the US-based distributor, was corporately headquartered out of Birmingham, Alabama, and they're the ones who made the mess out of the trademark that ultimately led to the whole Flying C confusion and their QC was horrid. The only thing they got right was sending out tons of samples to guitar magazines and letting Eric Barbour promote the hell out them to hi-fi snobs.
The electro harmonics (sovtek) and various tubes selected by TAD is very often the cheapest you can buy in music stores here in scandinavia, and therefore what musicians buy.
TAD has a very good reputation in the US, but I don't have any personal experience with them since I stopped doing repairs before they hit the market. I have more than enough NOS RCA 6L6GC's that I shouldn't ever need them anyway and I prefer Ruby for their EL-34B's and pretty much any big bottled 6CA7. Sovtek stopped making those 15-20 years ago and the set I got about ten years ago was NOS at the time and came in a turqoise and white Sovtek box. Its construction is identical to the GE 6CA7 except for the crimps on the plate welds.
One problem, of course, is that a musician often pulls out worn 6CA7's and install new 'bettter' EL34's without checking the
bias. Most of the HD130/65's I've had here with tube drivers, also had old american 12AX7 - suggesting this was never replaced.
And, not everyone can hear that an amp is due to be serviced, thats for sure - no tube lasts forever.
Agreed and 90% of most amp problems are just musicians messing in things they shouldn't and trying to save a buck that ends up costing them ten times more in the long run.
My bottom line, although you may be of the opinion that the Winged 'C' put out less power, when I measure amps (and tubes) after years of useage, they show very little wear in compearance to cheaper tubes.
Of course they're going to be longer lived; they have to be biased well below rated power to keep from cherrying. The bottom line with Svetlana/Flying C is that almost none of their power tubes actually meet their published data sheet specs for output power. They'll handle plenty of voltage biased cold, but what's the point?
Be aware that I'm new to this corner of the outpost forum, I do not visit these pages as a tech - but as a bass player. I do not spend much time
on the internet, but like the relaxed but very informative gibson pages.
I try to keep things informal and somewhat relaxed, but I do like to make a huge point of making sure that tech comments are put into the proper context because there is so much hype/misinformation/outright bullshit about amps on the internet. You HAVE experience working on amps using the tubes that you're talking about. That is, BY FAR, the exception rather than the rule on bass forums. I welcome your input and we certainly can have differeing views. The 'problem' I have is when folks claim knowledge that they clearly do not possess, and that is NOT the case with you.
I don't visit talkbass and such forums,
You're better off for it. Technical accuracy on Talkbass is as much of an oxymoron as truth in politics.
Since yesterday, I've read through the amps section here, and I can see that you are a skilled amp-factsman. Now, I couldn't help chipping in on this thread, as I play a musicman stack myself -and although being an all tube lover - have special feelings for these amps. I have also worked on many MM's. If I get too technical in my replies here, feel free to moderate me - I'm here for gibby amusement, not work 
You don't have anything to worry about. You are actually informed. There are others who speak authoritatively on amps who are not. Opinions presented as such and experience are always respected here. Self-aggrandizing BS is not, and as I said before, you have NOTHING to worry about in that department. It's nice to bounce experience off of other experienced techs. If you're interested, I am a member of another forum that's all about working on amps that is every bit as laid back as this place with guys who have been working on amps for decades that will still take the time to explain to the guy who Googled the forum and wants to put 6V6's in his Fender Twin why he shouldn't do it in as plainspoken terms as possible, but always with the experience, knowledge base, and references to conclusively support that advice should the need arise to provide it.
Other forums have set a tremendously bad example by treating disagreement or even discussion from differing viewpoints as fighting, and because of that, lots of bad information becomes accepted and treated as fact because it is "disrespectful" to correct it. You don't have to worry about disagreeing with me ever. I take legit disagreement just fine. I just won't tolerate bullshit.
