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    KT120s & tube cages

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    jhoak

    Posts : 46
    Join date : 2009-10-16
    Age : 58
    Location : Central Florida

    KT120s & tube cages

    Post by jhoak on Thu Jul 21, 2011 4:22 pm

    Has anyone tried a set of KT120s with a stock Dynaco tube cage on a VTA/ST-120?

    I want to buy a cage for my ST-120 but I'm concerned that the extra height of KT120s might keep it from setting properly.

    THANX!

    Bob Latino
    Admin

    Posts : 2378
    Join date : 2008-11-26
    Location : Massachusetts

    Re: KT120s & tube cages

    Post by Bob Latino on Thu Jul 21, 2011 5:07 pm

    Hi Jeff,

    The KT120's are just a hair too tall to fit inside a tube cage on the amp without the cage grazing the top glass of the tube. You have about 4 5/8 inches of clearance on the inside of a Dynaco ST-70/ST-120 tube cage. The distance from the top of the chassis to the top of the KT120 tube is also just about 4 5/8 inches. You can get the tube cage on but one or more tubes will probably be touching the inside of the perforated mesh of the tube cage. I don't recommend using a tube cage with the KT120 tubes ...

    Bob

    jhoak

    Posts : 46
    Join date : 2009-10-16
    Age : 58
    Location : Central Florida

    Re: KT120s & tube cages

    Post by jhoak on Thu Jul 21, 2011 5:16 pm

    That's what I wanted to know before I spent the $$

    THANX!

    Bob Latino
    Admin

    Posts : 2378
    Join date : 2008-11-26
    Location : Massachusetts

    Re: KT120s & tube cages

    Post by Bob Latino on Fri Jul 22, 2011 8:08 am

    As an aside > If you use a Mullard GZ33 tube rectifier in your ST-70/ST-120, this tall tube at 5+ inches also won't fit under a tube cage.

    Regarding tube cages for Dynaco amps ... They ARE useful if you have pets or young children who may have "access" to your amps. Those tubes themselves are 300+ degrees F and will cause an instant burn if you touch a tube while the amp is running. The down side of using a tube cage are that the amp will probably run a little warmer. Yep - I know that there are perforations in the tube cage for air flow but the amp has to run a few degrees warmer with the cage on. The other downside is that the cage must be removed to reset the bias. What some tube cage users do is place the cage on the amp but don't screw it down. I don't think your cat/dog or your toddler will know enough to raise the cage by paw/hand ? To reset the bias you can just quickly remove the cage. I personally do not use a cage because I just like the looks of the tubes glowing - especially in a dimly lit room. I don't have any toddlers around anymore but Chris and I do have a cat. The cat has access to the amps but has never expressed any interest in the amps nor have I ever seen the cat walk near the amps. I guess whether you use a tube cage or not has to be a personal decision.

    If you do want a tube cage for your ST-70/ST-120 amp get in touch with Kevin at Dynakitparts. His reproduction ST-70 tube cages are extremely well made and are identical to the original ST-70 tube cages right down to the "Dynakit" label.

    Bob


    Last edited by Bob Latino on Fri Jul 22, 2011 2:09 pm; edited 1 time in total

    jhoak

    Posts : 46
    Join date : 2009-10-16
    Age : 58
    Location : Central Florida

    Re: KT120s & tube cages

    Post by jhoak on Fri Jul 22, 2011 9:11 am

    The idea has been abandoned and the person who was pushing me to adopt her cat has been told no.

    Not being able to “cage” the hot tubes was all the excuse I needed to avoid becoming a pet owner again.

    Thank you!!

    Westy56

    Posts : 58
    Join date : 2011-05-09
    Location : Albuquerque

    Re: KT120s & tube cages

    Post by Westy56 on Fri Jul 22, 2011 5:26 pm

    jhoak wrote:Not being able to “cage” the hot tubes was all the excuse I needed to avoid becoming a pet owner again.

    Thank you!!


    The cages seem like a giant heating element that heats any ventilating air passing through it.



    Just guessing. Rolling Eyes


    Steve

    WntrMute2

    Posts : 96
    Join date : 2010-11-21

    Re: KT120s & tube cages

    Post by WntrMute2 on Sat Jul 23, 2011 7:20 am

    Bob, is that a picture of you and your SO in your avatar?

    Bob Latino
    Admin

    Posts : 2378
    Join date : 2008-11-26
    Location : Massachusetts

    Re: KT120s & tube cages

    Post by Bob Latino on Sat Jul 23, 2011 8:17 am

    WntrMute2 wrote:Bob, is that a picture of you and your SO in your avatar?

    Yes - The avatar is myself and my wife (#3), Chris. It was taken at a beach by my wife's cousin. Chris is quite a bit younger than me (16 yrs). I still wonder what she sees in me ?

    Wife #1 and I parted company in 1997. I had two jobs at the time. She didn't like the fact that I would use some of my second (part time) job money to buy audio gear - SO - I used the extra money on a divorce lawyer instead.

    Wife #2 (1999 - 2004) sadly passed away from cancer on May 19th of 2004.

    Wife #3 (Chris) and I met though a mutual friend.

    Bob

    buchela

    Posts : 31
    Join date : 2011-03-09

    Re: KT120s & tube cages

    Post by buchela on Sat Jul 23, 2011 2:31 pm

    Ok BOB, no more second jobs.lol

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