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


    SP14 9v transformer question

    Share

    xlr8

    Posts : 68
    Join date : 2010-02-09

    SP14 9v transformer question

    Post by xlr8 on Tue Feb 05, 2013 8:35 am

    Hi folks! I've made some pretty good progress putting this thing together, but my 9v tranny and volume control arrived yesterday and I was wondering about the secondary side. First of all, all of the leads are different colors than anything I've seen in any of the build photos or the schem that came with this unit. Second, the notes on the spec sheet that came with it says that the 2 secondary windings cannot be used independently. They have to be in series or parallel. I have black, red, orange and yellow leads. Black and red are the 2 ends of one winding and orange and yellow are the other. My question is how do I orient these leads on the board? The spec sheet says to tie BLK to ORG and Red to yellow and end up with BLK and YEL as the 2 output leads. Do I need to splice additional BLK and YEL onto the existing ones to get power to both sides of the board? What would you do? Also, I was wondering about a voltage check procedure before I fire it up with tubes in it. What voltages and where?

    Thanks guys!

    tubes4hifi
    Admin

    Posts : 1286
    Join date : 2008-11-30

    Re: SP14 9v transformer question

    Post by tubes4hifi on Tue Feb 05, 2013 9:32 pm

    that must be the one I just sent out a few days ago, no one on this forum is gonna know what you're asking, so an email direct to me
    would have been the better direction, but glad I caught this post on a rare lull in work.
    First, the tech note is not accurate the way you interpret it, just look at the diagram, and the hookup is simple and obvious.
    The people who write up these things have to account for 100 different transformers and connection styles.
    BTW, to the other 99% who are out of the loop on this, our transformer supplier is out of biz for a couple months due to a fire.
    This replacement is a Triad VPT18 (dual 9v secondaries).
    Here's how you wire it.
    blue and violet connect together and go to one side of the 120vac input.
    gray and brown connect together and go to the other side of the 120vac input.
    The black and red pair go to one side of the SP14 filament inputs (left or right channel, doesn't matter),
    so that's 9vac into the filament supply, which gets rectified to 12vdc and then regulated down to 6vdc for the 6SN7 tubes.
    The orange and yellow are the other 9v pair that go to the other side of the PCB to the filament inputs.
    Any questions on this, email me directly
    info@tubes4hifi.com

    xlr8

    Posts : 68
    Join date : 2010-02-09

    Re: SP14 9v transformer question

    Post by xlr8 on Sun Feb 10, 2013 8:09 pm

    OK. I just didn't want to innundate you with emails. After speaking with a friend about it, I went ahead and wired up the other day exactly as you described above. I've been out of town most of this past week and have not been able to mess with it. My wife said the caps I was waiting on have arrived, so when I get home I plan to complete and post a photo or 2. Thank you very much for your help! Very Happy

    Sponsored content

    Re: SP14 9v transformer question

    Post by Sponsored content Today at 4:38 pm


      Current date/time is Mon Dec 05, 2016 4:38 pm