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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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    VTA120 - bass no longer present - fixed !

    fmorelli
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    fmorelli


    Posts : 20
    Join date : 2013-08-27
    • Post n°1

    VTA120 - bass no longer present - fixed ! Empty VTA120 - bass no longer present - fixed !

    Post by fmorelli Sat Dec 15, 2018 4:48 pm

    Hi all, have not been on the forum in a while. Hope you all are well!

    I could use a bit of help. My VTA120 has been running well for years. Copper cap, Gold Lion KT88s, time delay. They are pushing Klipsch Epic CF-4 v1s. The whole setup has sounded great for years. In the last couple of days, it sounds like the bass has completely left. Any thoughts on what's going on or how to check it out?

    Thanks guys!

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

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    Post by Bob Latino Sat Dec 15, 2018 7:11 pm

    fmorelli wrote:Hi all, have not been on the forum in a while. Hope you all are well!

    I could use a bit of help. My VTA120 has been running well for years. Copper cap, Gold Lion KT88s, time delay. They are pushing Klipsch Epic CF-4 v1s. The whole setup has sounded great for years. In the last couple of days, it sounds like the bass has completely left. Any thoughts on what's going on or how to check it out?

    Thanks guys!

    Filippo

    Hi Fillippo,

    I have here on record a VTA ST-70 (not an ST-120) that you purchased in August of 2013? but you could have bought the ST-120 second hand ? Your ST-70 is over 5 years old.

    1. How many hours are on those output tubes ? or how many years have you been using them ? If you estimate that those tubes are over 3 years old or have over 3000 hours, replace the output tubes.

    2. If the lack of bass is on BOTH channels, try a new center driver tube first.

    3. Have you ruled out the preamp that you are using with your amp as a source of the loss of bass ?

    Bob
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    fmorelli
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    fmorelli


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    • Post n°3

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    Post by fmorelli Sat Dec 15, 2018 10:48 pm

    Thanks, Bob. Really appreciate the advise!

    Oops ... sorry ST-70 ... not sure why I got that crossed up. I actually swapped the KT88s after a few years with fresh, as switched to the copper cap rectifier. But the driver tubes are original to the amp, which are Genalex ECC82's - sounds like all 3 should be replaced at this age/use? I should ask if you have any recommendations. The speakers have horns in them and if anything are a smidge on the bright side already.

    I'm sure it is not on the source side. This amp was a joy to build, and it powers the music in my guitar-making shop. Honestly the best bang for the buck piece of audio equipment I've ever gotten - it puts a smile on my face every time I turn it on.
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    Tube Nube
    Tube Nube
    Tube Nube


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    Join date : 2008-12-06
    Age : 61
    Location : Calgary, AB
    • Post n°4

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    Post by Tube Nube Mon Dec 17, 2018 11:48 pm

    How are buyers of the new issue Dynaco gonna get thiis kind of expert assistance? I guess they might come here, and when they do. . . maybe some will get the itch to upgrade their gear with VTA options.
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    deepee99
    deepee99
    deepee99


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    • Post n°5

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    Post by deepee99 Thu Dec 20, 2018 1:31 pm

    Tube Nube wrote:How are buyers of the new issue Dynaco gonna get thiis kind of expert assistance? I guess they might come here, and when they do. . . maybe some will get the itch to upgrade their gear with VTA options.
    What I find refreshing, too, is that Bob (and the rest of his Merry Men) will try to help out with issues totally unrelated to VTA/Tubes4Hifi gear. Try to get that kind of support from your average retailer or importer!
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    Peter W.
    Peter W.
    Peter W.


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    Join date : 2016-08-07
    Location : Melrose Park, PA
    • Post n°6

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    Post by Peter W. Thu Dec 20, 2018 2:35 pm

    deepee99 wrote:
    Tube Nube wrote:How are buyers of the new issue Dynaco gonna get thiis kind of expert assistance? I guess they might come here, and when they do. . . maybe some will get the itch to upgrade their gear with VTA options.
    What I find refreshing, too, is that Bob (and the rest of his Merry Men) will try to help out with issues totally unrelated to VTA/Tubes4Hifi gear. Try to get that kind of support from your average retailer or importer!

    A small community with large hearts - if occasionally snarky!
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    fmorelli
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    fmorelli


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    • Post n°7

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    Post by fmorelli Thu Dec 27, 2018 9:15 pm

    Alright I figured it out. So it turns out the ground connection for the front aux loosened up. Over time it broke the wire soldered to the back.

    Filippo

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