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    ST120 second choke mounting

    Mr C
    Mr C

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    ST120 second choke mounting Empty ST120 second choke mounting

    Post by Mr C on Fri Aug 16, 2019 6:08 pm

    The second choke in the ST120 is held in by one screw and sits a little cockeyed in the picture. Has anyone drilled the chassis so it mounts straight and even with the other choke?
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    New2Tubez

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    Join date : 2018-03-20
    Location : NY

    ST120 second choke mounting Empty Re: ST120 second choke mounting

    Post by New2Tubez on Fri Aug 16, 2019 7:08 pm

    Someone on Bob's FB page did this:

    https://www.facebook.com/vta.amp.kits/photos/a.723510914424108/1387354951373031/?type=3&theater

    While I didn't change the mounting of the choke, I did use this build as a reference.
    Mr C
    Mr C

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    Join date : 2019-07-11
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    Post by Mr C on Fri Aug 16, 2019 7:32 pm

    Okay, Looks like you'd have to drill two holes. One for the choke and one to move the three lug terminal strip over. Certainly looks cleaner. Only thing is Bob doesn't include any extra screws.. Lol.. I'm at the point where I can make that mod. I'll think about it. Yea did see that picture already but didn't look at it closely. I haven't done the chassis wiring yet. Very nice. I'll print it out for reference.
    Bob Latino
    Bob Latino
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    ST120 second choke mounting Empty Re: ST120 second choke mounting

    Post by Bob Latino on Fri Aug 16, 2019 8:02 pm

    Mr C wrote:The second choke in the ST120 is held in by one screw and sits a little cockeyed in the picture.  Has anyone drilled the chassis so it mounts straight and even with the other choke?

    The design concept behind the VTA ST-120 was to fit a 60 watt per channel stereo amp into the chassis space of the original Dynaco ST-70. Neither the original Dynaco ST-70 or the VTA ST-70 need an extra choke. The VTA ST-120 (and the VTA M-125 AMPS) use two chokes because THEY HAVE higher current demands through the high voltage system. The choke being held by one screw or the choke being at a slight angle on the ST-120 is no problem. Note that the VTA M-125 is a new design and is a not a copy of any other tube amp and does have both chokes held by two screws and does have the two chokes parallel to each other. See M-125 wiring photo below.

    Bob


    ST120 second choke mounting M-125-interior-wiring-2
    HarryY
    HarryY

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    Join date : 2019-07-24
    Location : NY

    ST120 second choke mounting Empty Re: ST120 second choke mounting

    Post by HarryY on Fri Aug 16, 2019 8:29 pm

    On my ST-120 I installed the transformer in the position shown in the instructions.
    but I did put a small piece of double sided tape under the second screw hole and
    a rubber pat on the top so it would sandwich it tight in the chassis,

    I was tempted to drill it but thought if I do it may be difficult to
    install the delay board in the future if I change over to a SS rectifier.

    Mr C
    Mr C

    Posts : 57
    Join date : 2019-07-11
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    Location : Visalia CA.

    ST120 second choke mounting Empty Re: ST120 second choke mounting

    Post by Mr C on Sat Aug 17, 2019 3:21 pm

    Yea, I understood that it was that way to fit in the ST70 chassis. I was staring at and the thought went through my mind that if I drilled an extra hole it would sit even with the other choke. I see now the terminal strip would need to be relocated also. Just a thought.
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    StevieRay

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    ST120 second choke mounting Empty Re: ST120 second choke mounting

    Post by StevieRay on Sun Aug 18, 2019 8:38 pm

    It will stay put just fine; don’t sweat over it.

    Besides, drilling that pretty stainless chassis is a PITA, and if you make a mistake it will be unsightly, costly, or both.

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