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    How to wire and how to NOT wire a VTA amp kit - photos ...

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    tubes4hifi
    Admin

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    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by tubes4hifi on Thu Feb 16, 2012 12:17 pm

    since Bob didn't post the "supposed to look like this" photo for TubeNube, here you are . . .


    Tube Nube

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    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by Tube Nube on Thu Feb 16, 2012 12:39 pm

    And a thing of beauty it is!

    Sal

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    Location : Central New Jersey Dynaco-ST70.com

    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by Sal on Thu Feb 16, 2012 1:32 pm

    Thanks for the compliments.

    Sal

    Luddite

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    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by Luddite on Thu Feb 16, 2012 1:45 pm

    Ah-ha, those chokes seem to fit in the chassis much better. What is their source?

    Best Regards,
    Charlie

    Sal

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    Location : Central New Jersey Dynaco-ST70.com

    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by Sal on Thu Feb 16, 2012 1:56 pm

    Dynakitparts.com has the C 354 chokes in stock.

    Sal

    baddog1946

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    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by baddog1946 on Thu Feb 16, 2012 2:26 pm

    Hey are those different bias resistors?
    They look like 1/2 watt resistors. Not the same ones as in the first amp picture nor what Bob seems to recommend. Are they big enough?

    Bob Latino
    Admin

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    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by Bob Latino on Thu Feb 16, 2012 3:20 pm

    The photo that Roy posted is an early ST-120 photo. Shortly after the introduction of the VTA ST-70/ST-120 amp kits, the four bias resistors on both kits were changed from 1 watt to 2 watt resistors. The 2 watt resistors better withstand long term exposure to heat inside the amp.

    Bob

    HiGHFLYiN9

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    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by HiGHFLYiN9 on Thu Feb 16, 2012 4:36 pm

    Beautiful wiring Sal Smile

    Here's mine, not nearly as neat but not quite spaghetti either Wink


    davidness

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    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by davidness on Thu Feb 16, 2012 5:01 pm

    HiGHFLYiN9 wrote:
    Here's mine, not nearly as neat but not quite spaghetti either Wink

    I love those cmc-style sockets with the backside mounting card. When I build my next amp I'm going to use them everyplace I can.


    baddog1946

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    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by baddog1946 on Thu Feb 16, 2012 9:48 pm

    where did you get those CMC octal sockets?

    davidness

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    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by davidness on Fri Feb 17, 2012 12:46 am

    eBay. Just search for 'CMC Socket'. I just found both the octal sockets, plus the PCB wire-connection boards, which are important, plus really cool. They make assembly really easy, plus it makes changing of the sockets down the road much easier.

    I have the octals, and I have the 9-pin sockets for the small tubes (although I don't think they'd work with VTA boards).

    danskman

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    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by danskman on Fri Feb 17, 2012 5:50 am

    HiFly, you did a NICE and serious job!

    Blitzen

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    Join date : 2009-07-10

    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by Blitzen on Sun Feb 19, 2012 1:03 pm

    I don't understand how those CMC sockets with PCB connectors would make it easier to change sockets. Wouldn't you need a a special soldering tool to heat all the socket pins at the same time? (Well, maybe then it would be easier!)

    davidness

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    Join date : 2010-09-15

    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by davidness on Sun Feb 19, 2012 1:27 pm

    You don't need to unsolder your wiring. You just remove the solder on the socket pins using a solder sucker or dewicking braid. Swap sockets and solder the PCB back on. Granted, I know nothing about building an amp, but because I don't have much experience, this seems like it would easier.

    Mostly though, I like the firm connection these sockets make with the tubes. I have another amp where I have real problems with the tubes making a good, reliable connection, even after numerous attempts to bend the socket 'flanges' to retension them. Maybe I'm wrong, but these just seem to be the highest quality sockets. In a hobby where spending hundreds of dollars on wires, record needles, and tubes is commonplace, this seems like a reasonable upgrade.

    Blitzen

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    Join date : 2009-07-10

    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by Blitzen on Sun Feb 19, 2012 2:47 pm

    davidness wrote:You don't need to unsolder your wiring. You just remove the solder on the socket pins using a solder sucker or dewicking braid. Swap sockets and solder the PCB back on. Granted, I know nothing about building an amp, but because I don't have much experience, this seems like it would easier.

    Mostly though, I like the firm connection these sockets make with the tubes.

    Solder suckers and braid don't remove every last trace of solder. If these PCBs fit at all closely against the pins, then solder is going to wick all around the pin. As soon as you remove the heat whatever solder is left will still hold the pin...
    It seems you would need a special circular tip that heated them all at once, if such a thing exists!

    deepee99

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    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by deepee99 on Sat Jun 16, 2012 2:11 am

    Bob Latino wrote:A typical issue .... The amp kept blowing fuses ... The biggest problem here is that he did not "shorten the transformer wires to an appropriate length" as outlined in the assembly manual. Even though not shortening the wires might not make any difference in the sound of the amp, excessive wire WILL make a difference in your attempts to figure out why the amp doesn't work correctly. It's just a confusing mass of "spaghetti" in there and it is hard to tell what wire goes where?

    Bob
    Bob if I remember from hanning days a little tip: always grab the leads exiting the transformer firmly with pliers whilst you do "The Twist" on the departing ends. It is possible to yank the wires out of the xformer otherwise. Maybe they are sturdier nowadays but I think it's a good caution.

    Alan-14

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    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by Alan-14 on Sun Jun 17, 2012 12:39 am

    Tube Nube wrote:A hah! Then we all have chokes that are equally wonky at best, which in a way, restores symmetry!

    We don't all have wonky chokes ... nothing a little filing cant fix ... Smile


    Tube Nube

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    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by Tube Nube on Mon Jun 18, 2012 4:19 pm

    Now THAT is a tidy job!

    Alan-14

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    Re: How to wire and how to NOT wire a VTA amp kit - photos ...

    Post by Alan-14 on Tue Jun 19, 2012 10:26 am

    Thanks Brenton ... I tried to keep it as neat and tidy as I could ... and actually surprised myself with how it turned out Razz

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