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The Dynaco Tube Audio Forum

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


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    Rectifier tube gone bad?

    FGub
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    FGub


    Posts : 3
    Join date : 2023-09-02
    • Post n°1

    Rectifier tube gone bad? Empty Rectifier tube gone bad?

    Post by FGub Fri Mar 22, 2024 8:54 am

    Hy

    I have my dynaco st70 VTA in use for just over a year now. Yesterday on startup I had no sound and noticed the rectifier tube was not lit. I toucht it and it came on.
    Today on playing music the amp stops producing sound and again the rectifier tube was not lit. But this time it didn't react on manupulation. I notised it was kind a lose in the socet.

    I checked the solderings on the rectifier tubes and checked for a blown fuse (not neceessary couse the other tubes all lit up.

    Howe can I check if the rectifier tube is gone.
    At the moment I don't have a spare.

    Anny suggestion on things to check or cause are greatly apriciated.
    Kind regards

    Frank
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    Bob Latino
    Bob Latino
    Bob Latino
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    Join date : 2008-11-26
    Location : Massachusetts
    • Post n°2

    Rectifier tube gone bad? Empty Re: Rectifier tube gone bad?

    Post by Bob Latino Fri Mar 22, 2024 9:08 am

    FGub wrote:Hy

    I have my dynaco st70 VTA in use for just over a year now. Yesterday on startup I had no sound and noticed the rectifier tube was not lit. I toucht it and it came on.
    Today on playing music the amp stops producing sound and again the rectifier tube was not lit. But this time it didn't react on manupulation. I notised it was kind a lose in the socet.

    I checked the solderings on the rectifier tubes and checked for a blown fuse (not neceessary couse the other tubes all lit up.

    Howe can I check if the rectifier tube is gone.
    At the moment I don't have a spare.

    Anny suggestion on things to check or cause are greatly apriciated.
    Kind regards

    Frank

    Hi Frank,

    Check to see if you have any bias voltage on all four of the output tubes ? If you have no bias voltage on all four output tubes, the most likely cause is a bad rectifier tube. Also, always keep a spare rectifier tube in your home. The rectifier tube is the tube most likely to go bad on these amps.

    Bob

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    FGub
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    FGub


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    • Post n°3

    Rectifier tube gone bad? Empty Re: Rectifier tube gone bad?

    Post by FGub Fri Mar 22, 2024 9:23 am

    Thank You Bob,


    indeed no bias on all 4, just orderd 2 new rectifier tubes and a set of driver tubes as well.
    Also orderd two 4007 diodes and will do the yellow page mod.
    Next time i will have spares and can continue enjoing my best hifi purchase up to now Rectifier tube gone bad? 1f603

    Frank

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    halfpint6664
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    • Post n°4

    Rectifier tube gone bad? Empty Fuse blowing-Rectifer tube shorted

    Post by halfpint6664 Sat Apr 13, 2024 10:09 am

    I did a good enough job building the unit but don't want to try to trouble shoot. Looking for a GOOD place to repair my unit. VTA ST 70. Any suggestions welcome. Unfortunately emailed tubes4hifi TWICE with no response back. Thanks in advance.
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    peterh
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    • Post n°5

    Rectifier tube gone bad? Empty Re: Rectifier tube gone bad?

    Post by peterh Sat Apr 13, 2024 2:25 pm

    halfpint6664 wrote:     I did a good enough job building the unit but don't want to try to trouble shoot. Looking for a GOOD place to repair my unit. VTA ST 70. Any suggestions welcome. Unfortunately emailed tubes4hifi TWICE with no response back. Thanks in advance.
    It helps if you give a hing on where you are located
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    halfpint6664
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    halfpint6664


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    • Post n°6

    Rectifier tube gone bad? Empty Re: Rectifier tube gone bad?

    Post by halfpint6664 Sat Apr 13, 2024 6:17 pm

    Sorry. I'm located in Traverse City, Michigan
    I'm also willing to pay shipping both ways in necessary.

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    Bob Latino
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    • Post n°7

    Rectifier tube gone bad? Empty Re: Rectifier tube gone bad?

    Post by Bob Latino Sat Apr 13, 2024 8:18 pm

    halfpint6664 wrote:    Sorry. I'm located in Traverse City,  Michigan
    I'm also willing to pay shipping both ways in necessary.


    For repair on any VTA or Dynaco type tube amp get in touch with Joe Statkevicus in Tucson, AZ. Joe has extensive experience building VTA and Dynaco amps. You can contact Joe at this Email address > k3tye@earthlink.net. If you want to talk to Joe by phone, I am sure that he will give you his phone number.

    Bob

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    halfpint6664
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    • Post n°8

    Rectifier tube gone bad? Empty Re: Rectifier tube gone bad?

    Post by halfpint6664 Sun Apr 14, 2024 10:29 am

    Thanks Bob. I new you would come through.
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    • Post n°9

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