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Lifespan of good power tubes?

Discussion in 'Amp Central Station' started by telewacked, Apr 7, 2004.

  1. telewacked

    telewacked Tele-Holic

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    the orginal gent..

    I just received a pair of JJ's from Bob at Eurotubes....he was real nice on the phone and gave me some advice about biasing.
    I'm anxious to get them installed..

    Thanks for all the advice...

    fwiw - I've heard stories about GT over the years too, so I've stayed away and have dealt with Willie (LValve) in the past and now wanted to try the JJ's so I called Bob. The tech's in my area (formerly Wichita and now KC) seem to like GT for some reason though. It's all most of them carry.
     
  2. e-merlin

    e-merlin Doctor of Teleocity

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    FWIW, Fender and Ampeg amps (among others) come with Groove Tubes. Have they been duped? I think there is a lot of rhetoric spewing on this thread and I've seen no hard core evidence to back up some of the libel that's been thrown around.

    I have no affiliation with GT and I personally get my tubes from Bob@Eurotubes because he treats me well and helps me get the tones I'm after. However, I don't think it's fair to name call and categorize just because someone doesn't agree with your assesment of things. If you don't like the way someone does business don't do business with them. If you have a personal experience you'd like to share by all means share it so we can understand your aversion to a certain company. If you don't have a personal example, you're just parroting what others have said.
     
  3. jumpnblues

    jumpnblues Friend of Leo's

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    Total HRS As A Means Of Determining Tube Longevity...

    ...I'm not sure how accurate it is, but if I correctly recall, something in the literature that I received with the Dr.Z Route 66 I used to have (fabulous amp, wish I could have afforded to keep it) stated the total hrs for the GT KT66's were around 11,000 hrs. I'm not even sure if that info. was from Mike Zaite (Dr.Z) or Mr. Pittman. I don't know Mr. Pittman, but I do know Mike and if that figure was an estimate from him you can likely take it to the bank. Hope this helps. 8)
     
  4. Silverface

    Silverface Poster Extraordinaire Platinum Supporter

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    With larger amp manufacturers much of the actual parts content is dependent on finding suppliers with sufficient liability insurance coverage. It's a sad fact, but a large-scale outfit can't take a chance on using high-quality stuff from "boutique" suppliers, who have minimal...if any...liability insurance. the way things are nowdays, if there was a fire that could be related to an amp, lawyers would go after the makers of every *part* of that amp - tubes, speakers, transformers etc.

    It's likely one reason you don't see WeberVST speakers in Fender amps - it's not a quality issue, it's simply a liability one. Same with tube suppliers - if something goes dangerously wrong, the smaller guys don't have the insurance resources. You're not going to find a small manufacturer who carries a million or two of product liability insurance.
     
  5. Stan Martin

    Stan Martin Tele-Afflicted Silver Supporter

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    yes I DO have a problem

    :rolleyes:
     
  6. e-merlin

    e-merlin Doctor of Teleocity

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    Guess you should go back and read the thread.

    Yes, most of us were aware of that.

    Well, this is a first for me. I've never been called PC before. I'm still waiting for an example of "the fact".

    Like I said before, if you have a specific example that happened to you then post it so we all can learn. Otherwise you are just buying into someone else's hype and regurgitating that.

    Better yet, if you can run a similar company better, get crackin' and let me see you're smoke. Otherwise you're no better than those you are running down. I've recently become fond of the saying "Put up or shut up." That is if your skin is thck enough.
     
  7. Stan Martin

    Stan Martin Tele-Afflicted Silver Supporter

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    x

    eom
     
  8. Tremo

    Tremo Banned

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    Re: the orginal gent..

    Let us know how you like them. Please keep us posted, and preferably over on the Amp Workshop board, it's a good place, good guys hang there. Those JJs are still pretty new, and we still need to keep an eye on them for expected lifespan, or anything unusual that will only manifest itself over time.

    You're welcome.
     
  9. Tremo

    Tremo Banned

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    Well you're entitled to your opinions, as are the rest of us. If you want to prevent any name calling or criticism of your hero GT, I might suggest you to start your own board, then you can censor it as you see fit. You might even try to out-censor CG on the FDP. Don't expect to see anyone knowledgable participating in your censored forums.

    Fender and Ampeg use GT for a couple reasons. They, being large volume OEMs, have to use current production tubes from all the usual suspect manufacturers. That means they have to buy them in bulk, and screen them to reject the duds, and match up the power tubes, and be responsible for warranty issues that are tube related. Now this is just a distraction for them in their business model, more hassle that takes away focus from their core business. Alternately, it makes more sense for them to buy tubes from a reseller who will handle the screening and matching for them. It relieves Fender and Ampeg of a headache. Enter GT, since that is precisely their business. I believe the way it works is Fender buys the tubes in bulk from the importer and has them drop shipped to GT. GT tests and matches the tubes, throws out the duds, silkscreens on their logo, and ships the good ones on to Fender. An added bonus is the hype factor, in that Fender now gets to advertise that they use Boob Toobz. BFD. No, they are not "duped", it's a good business decision from a manufacturing standpoint, but there is nothing special about GT, other than the advertising hype. Get a clue.
     
  10. Tremo

    Tremo Banned

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    Re: Total HRS As A Means Of Determining Tube Longevity...

    That's about a year and 3 months. If the tubes have a good vacuum, no internal contamination, and good cathode chemistry, they should be able to go that long. Another factor is their operating environment. How much vibration and mechanical shock they have to endure, and well as what power levels they're run at.

    Now, has Mike actually run a pair that long and verified that they didn't degrade beyond minimum spec? Or is he just guessing?

    If you want to use current production real KT66s, you have 2 choices. The Chinese "Valve Art" model, or the Russian/GT model. Both sound good. Neither one has reliability issues.
     
  11. e-merlin

    e-merlin Doctor of Teleocity

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    OK, Tremo, now you're calling me names. You are not ruffling my feathers, but your colors are showing plainly. If you read my first post (if you can really read) you'll see that I buy my tubes from Eurotubes. So, who's the simpleton?

    My argument is not that you can't have an opinion. It is that calling names and making accusations without backing them up is silly. It's saying "this is what I'm saying so it must be right." Pretzel logic. You have so much invested in this emotionally that you can't take criticizim of your opinions. Or offer informed ones.

    And obviously, you can't state your opinion without running someone else down. You must have a sad life if the only way you can make yourself look good is by calliing other people names. Why don't you bring some logic to your argument along with your passion?

    As far as whether his stuff is too expensive, you can vote with your pocketbook and buy somewhere else. How much do you know about his operation? I know absloutely nothing so I'm not qualified to price his stuff for him. I bet you aren't either. Nor do I buy his stuff because I can get what works for me for less money.

    You pricing GT stuff is like me coming to your job and telling you what you can make without knowing what you do. That's silly, too!

    So, if you want to call me names and whine and cry like a little school girl when someone disagrees with you, go ahead. It only makes you look petty. However, if you come to the table with some solid arguments like a man, I'll be happy to hear what you have to say.
     
  12. Doc

    Doc Tele-Afflicted

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    Yes, GT does match and restap tubes. So do a lot of places. Thye often charge a bitmore for it as well. But, they are not awful or anything like that as I see it.

    Also some tubes, 6L6GE for example, are owned and made by them. So they are not all bought off others.
     
  13. Teleologist

    Teleologist Tele-Meister

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    Well at one point, I bought some genuine 'real deal' RCA 7025s for $20 ea. - the same price GT was charging at the time for Chinese 12AX7As. GT used to have(and probably still does) a private stash of NOS tubes sold thru a special group - I'd hazard a guess Aspen has NOS RCA or Sylvania 6V6GTAs in his personal DR, not the stuff they sell at Guitar Center. ;)

    But since price doesn't seem to matter, how about GT's 'rating' system???? Try comparing identical sets of power tubes with #4 & #7 ratings in the same class AB fixed bias amp. BUT rebias them to the same current ratings and you'll be hard-pressed to tell a significant difference in headroom or tone. Other vendors also rate tubes and it can be handy for people who don't want to rebias, but GT hasn't always been real clear about this. I wonder how many people go out and replace a good set of GTs with a different rating, when a turn of a screw could do the same thing...

    I do remember way back when GT was selling mostly new U.S., NOS, & military stuff and the tubes were really good compared to some other surplus vendors at that time. The U.S. tube plants shut down in the 80s and by the early 90s, things were getting really tight. Meeting demand meant that large vendors and OEMs like Fender had to go overseas. I don't think Aspen and others would have considered buying and re-opening U.S. tube plants if they were really happy with the imports. Their plans got kind of messed up in the late 90s by all the military base-closings and ship decommissionings that put container loads of U.S. JAN tubes on the market at very reasonable prices.

    Contrary to urban myth, tube-making is not totally dead or prohibited in the U.S., it's just very expensive given the volume. There's a company called Richardson Electronics that makes industrial tubes right here in Illinois. They re-ran some WE 300Bs a few years back - you don't want to know the price.....
     
  14. gtrplr2

    gtrplr2 Tele-Meister

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    I have a 1960 Gretsch 6150T amp that I received for Christmas that year. It still has the original tubes, and they are RCA. I have never replaced them, and the amp gets played at least 5 hours a week to this day.

    Jeff
     
  15. Tremo

    Tremo Banned

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    Yes, there are still tubes being made here in the USA. Witness the microwave tube industry. Teledyne, Litton and CPI. They make TWTs, klystrons, magnetrons, switch tubes, etc.... Yeah, they're way different than a 6L6, but they still are vacuum tubes with heater, cathode, etc... And of all places, all 3 of those companies are located in California, where the pollution rules are the most strict. Those old megawatt DEW line klystrons are about 14" in diameter, and 10' long. They run at about 100kV, and the output waveguide is the size of air conditioning duct (500 MHz).
    However, the 12AX7, 6L6 stuff is no longer made here, even GT.
     
  16. Tremo

    Tremo Banned

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    Well, not quite, Doc. Go read about this on Amp Workshop. Seems like Pittman bought the machines to make them, and resold the machines to China. Pittman bought the explosively clad plate material (what's left of it), and the micas. That's all the USA content in the GT6L6GE. The rest of the tube's guts, as well as it's assembly, apparently is Chinese. Seems like some other tube dealer got a shipment of tubes from China, and they were the 6L6GEs, by mistake.

    More hype and misinformation from GT?
     
  17. cowboytwang

    cowboytwang Poster Extraordinaire

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    If this is true then someone should file charges against GT. They still list MADE IN USA on those tubes and say on their literature and website that they are 95% USA components.

    From GT website:

    USA/GT reissue which is 95% USA components made on the original General Electric machines, the original tools, dies, materials and processing formulas as acquired from the liquidation for the last American tube factory in Owensbororough Kentucky.
    The most expensive (because of the the high US content)


    It is illegal to advertise or sell a product tht says " Made In USA" if a certaian percentage is not made here.
    Someone out in San Fernando needs to stop by the GT factory and snoop around to see if they are making anything.


    As for the rest of Aspen's hype,bs, or misinformation. If you ever get a chance to talk to the guy, he really believes everything he says. He does seem like a very smart guy, a little lost in himself, but smart.


    Back to the life of power tubes,
    I have a set of old mid '60s Sylvania bigbottle 6L6 tubes in a '66 Pro that have been in there for over 15 years and they still sound great.
    Then I've had some tubes that don't last at all.
    It's almost like trying to guess when your front porch light is going to burn out. There is just to many variables to pinpoint how long they will last.
    When they sound bad or stop working- change 'em.
     
  18. cg73cmc

    cg73cmc Tele-Holic

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    Screened Tubes (Long)

    First of all "Amp Workshop" is not a definitive authority on tubes. Most of the folks who post there, like Tremo, have an anonymous profile -- check out Tremo's -- his profile is "John". So you don't know who is posting what over there or if they are even authoritative. And anyone who uses personal attacks and name calling whenever someone disagrees with them -- then you have to suspect their motivation anyway.

    Second, I -- and a lot of others -- buy "screened" tubes. I could care less where they are manufactured -- or who's doing the screening, as long as when they arrive at my house they work when I plug them in. My background is military electronics and I worked on A LOT of tube equipment. I can tell you, that when tube electronics were prevalent in the military, we had HUGE issues with quality. No 2 tubes are created equally -- right off the assembly line.

    If they were -- you'd never have to "match" PA tubes -- they would always be matched.

    If they were, you'd never have to "rebias" -- every tube you dropped in the circuit would have the same characteristics as the broken one you pulled out of it had when it was functioning.

    If they were -- then I would have never had to realign the entire front end of every radar receiver that I replaced a tube in back in the old tube days. Tubes were a headache, because replacing one tube often changed the way the equipment operated and you had to go back and realign the whole equipment to account for the way that new tube was performing in the circuit.

    If they were -- there never would have been so many "tube testers" back in the day when vacuum tubes were plentiful. The fact is -- the first rule of vacuum tubes back then was "before installing new tube in equipment -- TEST IT IN A GOOD TUBE TESTER". The reason this was -- is because new tubes were often bad.

    I used to order 6 tubes every time I had to replace one tube -- that was so I could guarantee that I could get at least a couple out of stock that WORKED -- and so that I could then pick the best performing one. Sometimes a "good tube" was only a marginally good tube.

    BURN IN on a tube is good service in my opinion. New tube "mortality" in a ciruit is very high. This is because the tubes characteristics "change" after they have been under "heat" and operating for awhile. If you have a supplyer that burns in the tubes -- then tests them after burn-in before they send them to you -- then you are more likely to experience FEWER headaches with tubes.

    My tube background? Here is a list of equipments ...

    AN/URC-21
    AN/SPS-10
    AN/BPS-15
    R-1051 (A rotating TUBE magazine front end!)
    AN/SPS-53 (THE KING OF TUBE NIGHTMARES)
    AN/SPA-25 (Back when it was tubes)

    And many others that I've since (thankfully) forgotten!

    The tubes I got out of stock -- are the same JAN NOS tubes that you buy for your guitar amps today. Yes, I did a lot of work with "specialty" tubes -- magnatrons and reflext klystrons -- stuff you'd never see in a guitar amp. However, my headaches with these tubes were few. Most of my problems were caused by 12AX7's; 6V6's; EL-84's; you name it.

    So, if anyone out there wants to call those of us who buy "screened" tubes idiots -- fine. But you're not speaking from a position of knowledge.

    And if anyone out there wants to buy "unscreened" and "unburned" tubes -- I wish you well -- seriously. I respect your opinion -- I hope you'll respect my opinion, and the others of us who buy screened tubes -- whether it's from GT, KCANOSTUBES, or any of the other many tube "screeners". I find it offensive when someone like Tremo uses terms like "get a clue" to make his point.
     
  19. Silverface

    Silverface Poster Extraordinaire Platinum Supporter

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    Mark, almost everyone buys screened and/or burned-in tubes.

    But the point I think that was being made is that GT charges a lot more for them than others, when they are often common, inexpensive tubes - when purchased from other suppliers without the "GT" logo...and it's thought GT also overhypes their products (in some people's opinions).

    The notes about Amp Workshop - many of the guys over there are professional amp techs. not radar techs, guitar amp techs who deal with this stuff daily. Some of them can be a little abrasiove at times, but I've found them to be well-versed in guitar amp/tube technology.

    Cowboytwang - the GT 6L6GE's I have do not say "made in USA" anywhere on them, and I haven't seen that phrase used - GT may have the old equipment, but that doesn't mean it's all being used in the USA.
     
  20. cg73cmc

    cg73cmc Tele-Holic

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    I agree Silverface ...

    Everyone has his right to his own personal opinion on his tube supplier - without being called an idiot for his personal preference. I will also concede to you that GT does charge more. I use GT only because of the one guy in their SAG shop that I trust and correspond with on a regular basis. I happen to LIKE the guys that I've met (online) that work there (but I also have to admit -- until this thread, I never knew who Aspen Pittman was!). Hype in GT marketing? Perhaps -- I never read much of their marketing. When I approached them many years ago -- I was just looking for a good tube supplier of SCREENED tubes because I have no desire to relive my early days as an Electronics Tech in the Navy. Most of my hair is gone now -- not because of old age -- but because I pulled it out back in the heyday of "tubes"!! I'm telling you -- tubes are the way to go in an amp (IMO) - but they can be a hassle!

    You are also right I think when you say that most folks buy screened and/or burned in tubes. That was a peripheral point I was trying to make in pointing out the part about "matched" PA's. Who doesn't put a matched set in their amps? And who's doing the matching? Certainly not (for the most part) the individual owners of those amps. They are buying these tubes from someone that "screened" and matched them.

    When I read through this thread though -- I saw a lot of stuff about how GT testing was redundant -- because "any manufacturer" worth his salt would test his tubes before they left the factory. That may be a reasonable expectation for any manufacturer -- I'll agree to that. But I won't agree that it's a reality. There is value added in a "QC POINT" beyond the Chinese and Russian factories that most of these tubes are being manufactured in -- because their QC -- imho -- is fairly poor.

    Now, as far as a guitar amp techs experience being more valid than mine (which is more radar and comms). I agree to a point. I think an amp tech is more qualified to speak about how certain tubes sound in an amp. They are more qualified to talk about what tubes can be substituted here and there in an amp. However, they actually have LESS experience with tubes under severe stress than anyone who worked with them in military equipment. Military tubes were used 24/7 in critical equipment that had to ALWAYS operate. Common guitar amp tubes were used in frequency circuits all the way up to the UHF range. So although a guitar amp tech is probably more qualified to talk about guitar amps -- he is not necessarily more qualified to talk about tube performace when it comes to shooting and moving electrons from point a to point b. In my opinion, someone who has seen tubes under a variety of conditions and applications -- is more qualified to talk about that. Don't take that as a demand from me that you place more stock in my opinion here than someone elses -- I'm not asking that at all. However, I think you can understand why I personally value my own opinion more than someone else who's (a) Anonymous; (B) Using name calling and derrogatory words to derride those with a different opinion.

    By the way -- the best guitar amp tech I personally know has a background in both Military and Guitar applications -- and he works for a popular tube screener.

    My main beef here was some guy (Tremo) coming into a thread he didn't start to throw accusations around and belittle people who use GT's. I AM an Electronics Tech -- that is how I have made my living. I have worked in the business for 22 plus years (and before that in my uncle's Motorola TV shop in High School) -- and I can tell you -- Tremo is not qualified to call us idiots. And it really ticked me off -- and a few others it appears in this thread -- when he did.
     
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