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    How long a break-in time for JJ output tubes?

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    deepee99

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    How long a break-in time for JJ output tubes?

    Post by deepee99 on Sun Jul 02, 2017 1:13 pm

    Every now and then a recovering tube-roller goes on a runner. I tried a stash of JJ KT-88s in my Sachs-modded ST-120 and gave them a pre-emptive run in, in excess of 20 hours. The cannon-fire on 1812 Overture sounds like an owl puking down from a high tree-branch onto a steaming hot cow-patty. I can't listen to 'em. My own rules say give any new tube at least 100 hours but I cannot listen to the JJs that long, sounding the way they do. Is Patience the guiding god here, or should I just leave them on the curb?
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    peterh

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    Location : gothenburg, sweden

    Re: How long a break-in time for JJ output tubes?

    Post by peterh on Sun Jul 02, 2017 1:43 pm

    deepee99 wrote:Every now and then a recovering tube-roller goes on a runner. I tried a stash of JJ KT-88s in my Sachs-modded ST-120 and gave them a pre-emptive run in, in excess of 20 hours. The cannon-fire on 1812 Overture sounds like an owl puking down from a high tree-branch onto a steaming hot cow-patty. I can't listen to 'em. My own rules say give any new tube at least 100 hours but I cannot listen to the JJs that long, sounding the way they do. Is Patience the guiding god here, or should I just leave them on the curb?
    Restore the amp to original configuration. If that doesn't help , change speakers.

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    deepee99

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    Re: How long a break-in time for JJ output tubes?

    Post by deepee99 on Sun Jul 02, 2017 2:09 pm

    peterh wrote:
    deepee99 wrote:Every now and then a recovering tube-roller goes on a runner. I tried a stash of JJ KT-88s in my Sachs-modded ST-120 and gave them a pre-emptive run in, in excess of 20 hours. The cannon-fire on 1812 Overture sounds like an owl puking down from a high tree-branch onto a steaming hot cow-patty. I can't listen to 'em. My own rules say give any new tube at least 100 hours but I cannot listen to the JJs that long, sounding the way they do. Is Patience the guiding god here, or should I just leave them on the curb?
    Restore the amp to original configuration. If that doesn't help , change speakers.

    Then why do McShane's GL KT-88s and the Chinese KT-88 tubes work perfectly in these holes? I'm not going to re-configure everything just around a faulty quad of output tubes. I'd send the JJs back to the vendor but it's cheaper just to toss them in the trash. Work with me here. If they're such a great tube as you say the JJs are, how long need I wait to get a decent sound out of them?
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    peterh

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    Re: How long a break-in time for JJ output tubes?

    Post by peterh on Sun Jul 02, 2017 2:27 pm

    deepee99 wrote:
    peterh wrote:
    deepee99 wrote:Every now and then a recovering tube-roller goes on a runner. I tried a stash of JJ KT-88s in my Sachs-modded ST-120 and gave them a pre-emptive run in, in excess of 20 hours. The cannon-fire on 1812 Overture sounds like an owl puking down from a high tree-branch onto a steaming hot cow-patty. I can't listen to 'em. My own rules say give any new tube at least 100 hours but I cannot listen to the JJs that long, sounding the way they do. Is Patience the guiding god here, or should I just leave them on the curb?
    Restore the amp to original configuration. If that doesn't help , change speakers.

    Then why do McShane's GL KT-88s and the Chinese KT-88 tubes work perfectly in these holes? I'm not going to re-configure everything just around a faulty quad of output tubes. I'd send the JJs back to the vendor but it's cheaper just to toss them in the trash. Work with me here. If they're such a great tube as you say the JJs are, how long need I wait to get a decent sound out of them?

    30s, until fileament is warm and bias is correct.
    if they don't work, they seems faulty. Let the vendor measure them again. I assume
    you got them from eurotubes.
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    deepee99

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    Re: How long a break-in time for JJ output tubes?

    Post by deepee99 on Sun Jul 02, 2017 2:29 pm

    Yep, from Eurotubes. I don't mind a long blossom-time, just wondering how long. No offense given or intended. Just seems they take longer than most.
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    peterh

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    Re: How long a break-in time for JJ output tubes?

    Post by peterh on Sun Jul 02, 2017 3:27 pm

    deepee99 wrote:Yep, from Eurotubes. I don't mind a long blossom-time, just wondering how long. No offense given or intended. Just seems they take longer than most.
    It shouldn't be mer then a few minutes. Let eurotubes figure out ( if other kt88 sounds ok in your amp)
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    PeterCapo

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    Re: How long a break-in time for JJ output tubes?

    Post by PeterCapo on Sun Jul 02, 2017 5:22 pm

    deepee, do they sound awful with other kinds of music or just the 1812 cannons?  That's a pretty demanding passage.  But, if they don't sound good with other music...  Are they holding steady bias?

    JJ can be a bit perplexing sometimes, I don't know.  I had a circa 2003 quad of JJ E34L and I thought they were really nice.  Later, I tried a quad of JJ KT77 and they were unlistenable - sent them back.  Yet again, I have a very nice sounding quad of JJ EL84.  Hope you can get some kind of good resolution.
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    tubenutr

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    Re: How long a break-in time for JJ output tubes?

    Post by tubenutr on Sun Jul 02, 2017 6:23 pm

    deepee99 wrote:Every now and then a recovering tube-roller goes on a runner. I tried a stash of JJ KT-88s in my Sachs-modded ST-120 and gave them a pre-emptive run in, in excess of 20 hours. The cannon-fire on 1812 Overture sounds like an owl puking down from a high tree-branch onto a steaming hot cow-patty. I can't listen to 'em. My own rules say give any new tube at least 100 hours but I cannot listen to the JJs that long, sounding the way they do. Is Patience the guiding god here, or should I just leave them on the curb?

    deepee99,

    Just tuck them away in the tickle trunk and on a rainy day, drag them out and hook up your tv to a Nascar race and let them run for ??? hrs.
    I've have great luck with JJ's in both pre and power.

    Its worth a shot. Or you can send them to me gratis......................

    Mike

    Dogstar

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    Join date : 2014-06-23

    Re: How long a break-in time for JJ output tubes?

    Post by Dogstar on Sun Jul 02, 2017 10:59 pm

    Prior to the Genelex Gold Lion KT-88's and GZ34 I am currently running in my VTA ST-120 I was using TungSol KT-120's and a Webber SS rectifier and to be honest I thought the sound was much nicer than with the Genelex tubes which have at least 400 hours on them. There is nothing horrible about them ...but there is nothing phenomenol that I seem to remember from the KT-120's.

    The 6SN7's I'm currently experimenting with in an adapter in the center position of the preamp section seems to help but I'm somehow feeling I'd be much happier with another quad of KT-120's. Sorry for the thread jack but I know the GL KT-88 get such high praise here...I'm thinking maybe I got just a so so quad as did the OP with the JJ's.
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    jfine

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    Re: How long a break-in time for JJ output tubes?

    Post by jfine on Sun Jul 02, 2017 11:05 pm

    Never liked any JJ tube I have heard, my brother uses em in his guitar amps, didn't like em either. I use them to fill holes in gear I'm selling Smile
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    arledgsc

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    Location : SF Bay CA

    Re: How long a break-in time for JJ output tubes?

    Post by arledgsc on Tue Jul 04, 2017 11:23 am

    Same here.. never thrilled about JJ tubes but use them in guitar amps as they are dirt cheap in comparison to others.

    Dogstar

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    Answer to the question

    Post by Dogstar on Wed Jul 05, 2017 6:40 am

    OK OK....given the dislike for JJ tubes in general I have the best answer to the question:

    How long a break-in time for JJ output tubes?

    And the answer is:

    3 to 4 feet when dropped on a hard concrete surface.

    Not to be snarky of course... :-)
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    arledgsc

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    Re: How long a break-in time for JJ output tubes?

    Post by arledgsc on Wed Jul 05, 2017 10:57 am

    Dogstar wrote:OK OK....given the dislike for JJ tubes in general  I have the best answer to the question:
    How long a break-in time for JJ output tubes?

    And the answer is:
    3 to 4 feet when dropped on a hard concrete surface.

    Not to be snarky of course... :-)

    lol!

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