The Dynaco Tube Audio Forum

Dedicated to the restoration and preservation of all original Dynaco tube audio equipment - Customer support for Dynaco VTA tube amp kits, all Tubes4hifi.com products and all Dynakitparts.com products


    WZ68 Rectifier Blown?

    Share

    nathico

    Posts : 4
    Join date : 2012-04-27

    WZ68 Rectifier Blown?

    Post by nathico on Sun Nov 29, 2015 12:41 am

    Just blew a fuse on my st-120. When I went to pull rectifier, the cap slipped right off. Not seeing anything obviously blown. Is there a way to test the WZ68 to see if it is what caused the fuse to blow?

    Thanks for the help.

    sKiZo

    Posts : 1285
    Join date : 2013-04-01
    Location : Michigan USA

    Re: WZ68 Rectifier Blown?

    Post by sKiZo on Sun Nov 29, 2015 1:52 am

    I've heard of the cap coming off and the rectifier working fine. It's apparently just glued on, and the heat loosens it up.

    Easiest test would be to put in a spare and see if the fuse blows again.

    Make sure you re-tension the socket while you're at it. Loose connections sink ships, or something like that.

    nathico

    Posts : 4
    Join date : 2012-04-27

    Re: WZ68 Rectifier Blown?

    Post by nathico on Sun Nov 29, 2015 2:09 pm

    Thanks, just ordered a new Weber, if it blows the fuse I will have a back up now and will start over on trying to diagnose the problem. Thanks again

    Maintarget

    Posts : 208
    Join date : 2013-02-10

    Re: WZ68 Rectifier Blown?

    Post by Maintarget on Sun Nov 29, 2015 6:09 pm

    Same thing happened to me last week when I changed back to tube rectification I doubt the copper cap is bad.

    peterh

    Posts : 642
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: WZ68 Rectifier Blown?

    Post by peterh on Sun Nov 29, 2015 6:26 pm

    when the gz34 breaks(again) in my vta70 i think i will mount 2 1n4007 diodes and forget about
    tube rectifiers. Until then i'll be lazy and keep the music flowing.
    But that's me, ymmw

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: WZ68 Rectifier Blown?

    Post by deepee99 on Sun Nov 29, 2015 6:29 pm

    I've had Webers with loose cans; they'll run fine (and considerably cooler) without 'em on at all, but that exposes some pretty high voltages affraid
    One of many other things that will blow a fuse -- and sometimes take a rectifier with it -- is a red-plate event in one of your output tubes. I had a low-time KT-88 go south on me last week when the screen and control grids (pins 4 and 5) shorted to each other. Nice fireworks; the fuse put a stop to the nonsense and somehow the rectifier survived.
    The Webers work pretty hard in a Dynaco power supply and heat is their enemy. TMadden on this board has some inexpensive mods you (or he) can do to them that will beef up their current capacity and let them run cooler.

    nathico

    Posts : 4
    Join date : 2012-04-27

    Re: WZ68 Rectifier Blown?

    Post by nathico on Sun Nov 29, 2015 9:42 pm

    I was out of the room when the fuse blew, but did not see any signs of distress in the outputs. Was going on almost 4 years of daily use and frequent high volume, so hopefully just the rectifier. If there is a test, would love to check it, otherwise new Weber will be here this week.

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: WZ68 Rectifier Blown?

    Post by deepee99 on Sun Nov 29, 2015 10:04 pm

    nathico wrote:I was out of the room when the fuse blew, but did not see any signs of distress in the outputs.  Was going on almost 4 years of daily use and frequent high volume, so hopefully just the rectifier.  If there is a test, would love to check it, otherwise new Weber will be here this week.

    My blown KT-88 shows no physical signs of blowing; getter flashing is still pretty and there's nothing weird-looking inside. Fortunately I was in the room when things went pear-shaped. Looks can be deceiving.

    nathico

    Posts : 4
    Join date : 2012-04-27

    Re: WZ68 Rectifier Blown?

    Post by nathico on Sun Nov 29, 2015 10:40 pm

    Thanks, went ahead and checked connectivity, no shorts in the power tubes, runt kt-120. Checked all pins , only connective between 2 & 7 on all. Course does not mean something else is not wrong. Thanks for the tip on checking them.

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: WZ68 Rectifier Blown?

    Post by deepee99 on Sun Nov 29, 2015 10:54 pm

    Four years of steady use on the new generation of power tubes and the Webers is gettin' your money's worth.

    Sponsored content

    Re: WZ68 Rectifier Blown?

    Post by Sponsored content Today at 6:11 pm


      Current date/time is Wed Sep 28, 2016 6:11 pm