Vented cans for 12XX7 tubes.Great heat dissipation of tubes on the cheap.

Discussion in 'Audio Hardware' started by Kiko1974, Feb 19, 2018.

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  1. Kiko1974

    Kiko1974 Forum Resident Thread Starter

    I've been thinking about buying some vented cans I've seen at the great on-line shop of my friends from Langrex, and I finally got three of them for my EAR 834 "clone" Phono preamp. I got them today, slided the cans on the two 12AX7 and one 12AU7 tubes, and switched the Phono preamp on.
    They seem to work fine, after half an hour of the Phono preamp on they were quite warm but after an hour they well hot as hell. I wonder that without these vented cans what would happen with all this heat and if it would really affect the tubes life or performance, anyway, I don't think these hurt.
    They look ugly but as the tubes are inside the case they are not visible.
    What do you think about these?
    Just in case anybody is interested here's the link to get them:VENTED CANS MILITARY SPEC. (SUIT ECC82/12AX7 B9 SIZE) - Langrex [​IMG]
     
  2. ti-triodes

    ti-triodes Senior Member

    Location:
    Paz Chin-in
    I’d be afraid to put those on a set of vintage tubes. They look like they would wipe the delicate print off.
     
  3. Kiko1974

    Kiko1974 Forum Resident Thread Starter

    Yes, they could tear off the printing ink on tubes but if they extend their life then they're worthwhile.
     
  4. ti-triodes

    ti-triodes Senior Member

    Location:
    Paz Chin-in

    True, but it would be painful to remove the printing off a set of vintage Telefunkens or Bugle Boys. There are other solutions out there that do the same job. Check out some vintage stuff on eBay. I’ve seen some cover that have a slightly wider taper from the top to the bottom. Does the same job with no damage.
     
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  5. Kiko1974

    Kiko1974 Forum Resident Thread Starter

    Thanks for your reply. I'm afraid that I wouldn't know how to look for what you suggest on Ebay as English is not my mother languaje.
     
  6. ti-triodes

    ti-triodes Senior Member

    Location:
    Paz Chin-in

    Look up “tube shield”. That should give you a good idea. Good luck! :)
     
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  7. TarnishedEars

    TarnishedEars Forum Resident

    Location:
    The Seattle area
    What really wears-out a tube is its cumulative emissions, combined with its on and off cycles. But what wears-out the rest of the circuit is the heat. So I kind of doubt that these are going to benefit anything.
     
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  8. Kiko1974

    Kiko1974 Forum Resident Thread Starter

    Thank your for your help. I've looked for tube shields on Ebay and all I've found are the cover-like ones with a spring inside, I already have a pair of those and they don't stay put, and in addition to that they don't really touch the tube's surface like the ones I got today, these really get heat out of the tube surface believe me.
    Regarding tearing off the printing, I'm currently using a set of 3 NOS Matsushita 2x 12AX7 plus 12AU7x 1, they're inexpensive but I like them very much and their printing is very light ink that doesn't protrude from the tube's glass so it doesn't seem that printing may come off easily, actually I've put them in and out the tubes on them just to check this out and there's no damage to printing if this is done gently, with my Hitachi tubes this may be different as they have the kind of printing with the kind of ink that looks like engraved one, that ink may peel off. But the seller has giving me a trick, roll a Post It INSIDE the vented can, then slide the tube in and finally as the can is not closed by the top, pull off the Post it, this way ink will remain undamaged. And these can are not the kind of thing one takes off and put in again and again, why would one do that?
     
  9. John Moschella

    John Moschella Senior Member

    Location:
    Christiansburg, VA
    So somebody help me out with this. Why is this a good thing? Tubes are certainly designed to run at a certain temperature, and I bet the manufacturers of audio equipment voice their components at operating temp. Why do you want to screw around with this?
     
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  10. Kiko1974

    Kiko1974 Forum Resident Thread Starter

    I think you came to the right place to ask this kind of question. This wouldn't be the first time that an "of the selve" piece of equipment undergoes some kind of modifications, some even extensive ones, and that piece of equipment ends up performing better than as it came from the factory. Keep in mind that with any equipment some compromises use to be made, what is designed and what can actually be made at a cost effective price so the unit can be sold, the more the better and at high profit margins. I think even High End no compromise equipment can me modded so it performs at least DIFFERENTLY than as it comes from the factory to better suit the owner's tastes.
    My Phono preamp, an EAR 834 "cone" specifies the use of three 12AX7 tubes, but as a V3 which is used as a "buffer tube" on a cathode follower configuration I use a 12AU7 as it doesn't damage the unit and I like best how it sounds with a 12AU7 instead of a 12AU7.
    Anyway, these "vented tube cans" are just an easy and cheap "mod" that if it doesn't convince me Ican toss away.
     
  11. ti-triodes

    ti-triodes Senior Member

    Location:
    Paz Chin-in

    They’re actually used for cutting down RFI interference, not temperature control. Primarily in preamp tubes and tuner sections of receivers. They were very popular in the 50’s-60’s but have fallen out of favor in recent years with the decline of tuner sections in tube amps. IIRC, most people can’t hear any difference with them on, but YMMV. BTW, look real nice when they’re polished on a vintage amp. :)
     
  12. Kiko1974

    Kiko1974 Forum Resident Thread Starter

    The tubes on my EAR 834 "clone" Phono preamp are inside the preamp's case so I don't think RFI interference can be much of an issue, but I have noticed that the Phono preamp has became a little bit quieter,maybe it's because the toroidal transformer is very near the tubes, although it's also encased in its own case.
    I don't think these cans can hurt, right the opposite so unless I notice something weird with them on they're staying. And I don't have fancy tubes which logos and ink inscriptions can tear off when putting this on or removing them. And I've done enough tube rolling with all the tubes I have so I'm sticking with the Matsushita tubes are currently on.
     
  13. allied333

    allied333 Audiophile

    Location:
    nowhere
    12AX7s do not make enough heat to require the IERC tube shields. But, some tubes would benefit from operating cooler & the IERC shields do provide that vs a standard shield. On the other hand, I do not know if there is really any benefit of a cooler operating tube.
     
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  14. John Moschella

    John Moschella Senior Member

    Location:
    Christiansburg, VA
    thanks!
     
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  15. Kiko1974

    Kiko1974 Forum Resident Thread Starter

    My EAR 834 "clone" Phono preamp uses 3 tubes, following the specs of the designer, Tom de Paravicini, 3 12AX7 should be used. V1 tube does most of the amp for both channels, around75/80 % of the amp. V2 tube does RIAA de-eq and the rest of the amp. V3 is used as a "buffer" tube on a cathode follower configutarion to keep impedance down and reduce distorsion. This v3 tube can be changed for a 12AU7 tube, some say, according to posts on some forums changing V3 tube for a 12AU7 gives better performance, a wider soundstage and a sound with more "spark", which I agree, that's I use one after trying both. This V3 when used a 12AU7 is the one that heats the most, after less than an hour I can't touch the "vented can" as it's hot as hell. V2 12AX7 tube also gets rather hot, but curiously V1 tube which does most of the amp is the one that remains cooler. If I see a bad side effect by using these "vented cans" I'll remove them, in the meantime they'll stay where they are, they don't seem to do any harm.
     
  16. ti-triodes

    ti-triodes Senior Member

    Location:
    Paz Chin-in

    Cool. Like I said, YMMV. BTW, tube dampeners may have the same effect depending on what you’re looking for. There are many out there, but these are probably some of the best.

    Herbie's Tube Dampers
     
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  17. Kiko1974

    Kiko1974 Forum Resident Thread Starter

    Thank you for your reply. They look nice but only for damping, not to keep tubes cool. I think the one I got do a good job at it, I don't need damping, I have an EAR 834 "clone" Phono amp, the tubes are inside the case and this case is made of thick aluminium, it weights a ton so I think tubes inside of it are weel damped/isolated from any outer vibrations.
     
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