Early tube change-did I jump the gun?

Discussion in 'Audio Hardware' started by merlperl, Nov 28, 2022.

  1. bgiliberti

    bgiliberti Will You Be My Neighbor?

    Location:
    USA
    My experience as well...when they fail, it's usually shortly after installation. However, so far, I have not had this type of early failure in my limited experience with currently manufactured tubes, e.g., from China, or Russia. This makes me question how many NOS tubes I've bought are actually "virgin," given the relatively higher early failure rate compared to newly manufactured tubes.
     
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  2. bgiliberti

    bgiliberti Will You Be My Neighbor?

    Location:
    USA
    What precautions are there with NOS tubes, many of which were manufactured decades ago? Even reputable dealers are still relying on the word of their supplier, and so on up the line. They'll give you a return guarantee, but even they are at the mercy of what somebody said to somebody else who said...etc...
     
  3. Lowrider75

    Lowrider75 Forum Resident

    Location:
    Philadelphia, PA
    I haven't had early failures on "NOS" tubes purchased from reputable dealers; eg, Brent Jessee, Andy at VTS, Upscale.
    Failures have occurred from some Ebay vendors, but I've found a couple trustworthy sellers. But very few of their tubes are true NOS.

    Regarding relying on the word of suppliers, the experienced legitimate dealers don't. They have the knowledge and test equipment to know if a tube is true NOS or a "pull." It would be nice to know the provenance of a tube, but that rarely happens in this world of dwindling NOS supplies.
     
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  4. Frank Bisby

    Frank Bisby Forum Resident

    there are those that will tell you tube break in needs to happen again after they sit idle for an extended period of time. I believe Kevin Deal has a video where he talks about this at length and implores people to chill out on rolling their tubes. I’m inclined to believe this is true. Anytime I rotate equipment that has sat for a while it often doesn’t sound its best until it’s had some time to operate, this also generally includes a re basis when possible.

    but in your case, the tubes you rolled in weren’t “broken in” either. I have consistently found new production power tubes start to sound noticeably diminished when they get anywhere close to 2,000 hours. Replace them with a fresh set and it’s like getting a new amp, it’s very exciting. With signal tubes, I’ve not found the sound changes as much as they lose gain and and get noisy when they are reaching the end of their life and that should be closer to 5,000 hours in new production.

    I would guess you didn’t notice the slow decline of the power tubes when you were listening to them everyday and the ling break made it very noticeable. Just roll back in your signals and see if they are worth keeping, they probably are.
     
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  5. Bill Hart

    Bill Hart Forum Resident

    Location:
    Austin
    True that. I've used most of the usual suspects in the US as well as a few abroad. Brent will tell you that he doesn't regard NOS as meaning never used-- there is disclaimer language on his site. He is a stand-up guy though.
    I've had extremely good luck with Andy at Vintage Tube Services- downsides are that he is slow, and doesn't deal with some tubes- for example, I like a GEC u-52 rectifier- he's said he's never stocked it. How to tell beyond the reliability of the vendor-- condition of the tube itself I suppose, as well as provenance, if known. I found a matched quad of '70s era 6h30s that were originally sourced from Victor at BAT, purchased by a BAT owner, then sold to a friend who I trust.
    It isn't easy. The big vendors will occasionally offer NIB NOS at high prices. I don't think there are any bargains, though. The Russian tubes I get from Lamm for my amps- Vlad (RIP) had a stock of those and was always reliable in sourcing them though his prices reflected that- far more than E-Bay pricing but he'd match the tubes to the amps (some characteristic about the range of bias) and burn them in. Even with that, when I put new power tubes in the amps, I gradually burn them in myself, rather than doing what the car guys used to call the "Italian tune-up": take it out on the road and mash the go pedal to the floor.
    It's a jungle out there.
     
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  6. merlperl

    merlperl Forum Resident Thread Starter

    Location:
    Omaha, NE
    Thanks for your praise. This system came out very balanced physically and aurally. The cabinet dictated how I set it up. It just came out looking sexy! And sounding sublime.
    As for the tubes, I realized that I took them out to protect them while I was away. And perhaps there was some oxidation that I didn’t deal with.
    I had some low hour power tubes, and some totally new ones. Now I have two back up sets!
     
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  7. merlperl

    merlperl Forum Resident Thread Starter

    Location:
    Omaha, NE
    These are Tung Sol tubes-Russian. Not many options for them.
     
  8. merlperl

    merlperl Forum Resident Thread Starter

    Location:
    Omaha, NE
    Well in this case the tube change definitely refreshed the system. I think I may have gone overboard with the signal tubes and preamp tubes. But this hobby is all about going overboard, no?
     
  9. jonwoody

    jonwoody Tragically Unhip

    Location:
    Washington DC
    Have you ever tried the Gold Lion KT-77 repros in your SLI-80? I found them much better than current production Tung Sols in my old, not Cary, EL34 stereo amp.
     
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  10. merlperl

    merlperl Forum Resident Thread Starter

    Location:
    Omaha, NE
    I have used gold lion kt-88’s. I like them. Just had one red plate on me though! Now I’ve got some newer Mullard El-34s in there. I like that it can use a lot of different power tubes. And there are so many choices for signal, phase and even rectifier tubes for that amp. It’s truly a tube rollers dream.
     
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  11. jonwoody

    jonwoody Tragically Unhip

    Location:
    Washington DC
    Nice and trust me the KT77's are significantly better than the KT88's more of the EL34 type sound but better to my ears at least and many other ears I trust.
     
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  12. merlperl

    merlperl Forum Resident Thread Starter

    Location:
    Omaha, NE
    I’ll try some of those!
     
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  13. Salectric

    Salectric Senior Member

    Location:
    Maryland
    Absolutely correct! The GL KT77s are truly great tubes. GL KT88s are not in the same league at all.
     
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  14. merlperl

    merlperl Forum Resident Thread Starter

    Location:
    Omaha, NE
    Crap. Now I have to get some
     
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  15. mreeter

    mreeter Forum Resident

    Location:
    Kansas City
    I've got a fresh quad of the KT77's that I plan on rolling in the SLI-80 as soon as the Amp comes to fruition, still have some to go yet.
     
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  16. merlperl

    merlperl Forum Resident Thread Starter

    Location:
    Omaha, NE
    Have you found that some signal tubes have pins that are a bit narrower and that makes them static-ey sounding, especially when you touch them? How do you fix that?
     
  17. mreeter

    mreeter Forum Resident

    Location:
    Kansas City
    I started out with stock EH 6922 for the first time, they were TIGHT going in. Removed and put in a nice, nos pair of Philips PCC189's and they slipped in a little easier. I've found that most new production tubes (most I've tried) have larger pins than old stock. Rolling the n.p. tubes seems to expand the sockets somewhat.

    Drop in an old tube and they will seem loose (over a period of time) as the tube sockets expand. I've pinched the pin sockets back closer together on other Amps to tighten up the grip and that has always taken care of any static and the tubes seat much better.
     
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  18. merlperl

    merlperl Forum Resident Thread Starter

    Location:
    Omaha, NE
    I’ll try that! I have some plastic pokey tools I think were made for gun cleaning…
     
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  19. Lowrider75

    Lowrider75 Forum Resident

    Location:
    Philadelphia, PA
    That's the advice I got from a dealer and the manufacturer of my amp. Take care not to move the pin holders too much, they may need to return to original position.
     
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  20. mreeter

    mreeter Forum Resident

    Location:
    Kansas City
    Exactly, the tube sockets on the SLI-80 and others I have or had, the 9 pin sockets are very small openings, really depends on what the Mfg. uses. On those I use a sewing needle and gently work them back to 'normal', on larger sockets I use a small Awl.

    I'm sure some will have a critical word on this, but it has to be done once in a blue moon. Unless, you are one that doesn't enjoy rolling some tubes now and again. I for one have been addicted for more than a few years now :winkgrin:
     
    Last edited: Nov 30, 2022
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  21. Lowrider75

    Lowrider75 Forum Resident

    Location:
    Philadelphia, PA
    Since you just came out to the world, I will too. I'm a tube rolling addict.
     
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  22. mreeter

    mreeter Forum Resident

    Location:
    Kansas City
    It's a start, now I feel better, but I've not been to any meetings yet:winkgrin:
     
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  23. merlperl

    merlperl Forum Resident Thread Starter

    Location:
    Omaha, NE
    Same, at least with the Cary!

    my Audio Research stuff sounds sublime and does not need rolling at all. In fact if I wanted to, there aren’t too many options.
     
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  24. Lowrider75

    Lowrider75 Forum Resident

    Location:
    Philadelphia, PA
    Yeah, I never meet any AR tube rollers on the forums. Like you said, there's no need. Knock yourself out rolling the Cary.
     
  25. merlperl

    merlperl Forum Resident Thread Starter

    Location:
    Omaha, NE
    ARC makes it tough with their tube selections too. At least newer models. Try finding something to replace 6H30s!
     
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