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    Yet another new guy.....uffa!

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    cci1492

    Posts : 13
    Join date : 2016-05-09
    Age : 55
    Location : Bergen County NJ

    Yet another new guy.....uffa!

    Post by cci1492 on Fri Aug 12, 2016 9:31 pm

    Been lurking around for a long time, figured it was time to come out and post some pictures, perhaps it will help others in their build (you know who you are...hi LeGrace). I build the two slightly different, routed some wires around different ways on the second one. Have to take some pictures of them done, but trust me, they look just like the other ones other than some fat Chinese feet I installed on each. Decided on the KT120s from Jim. So far so good, been pushing the amps hard for several weeks now and they just keep playing wonderfully.

















    Last edited by cci1492 on Sat Aug 13, 2016 7:42 am; edited 6 times in total

    pedrocols

    Posts : 61
    Join date : 2014-11-24
    Location : Western MA

    Re: Yet another new guy.....uffa!

    Post by pedrocols on Fri Aug 12, 2016 10:16 pm

    Very nice!

    peterh

    Posts : 641
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: Yet another new guy.....uffa!

    Post by peterh on Sat Aug 13, 2016 2:18 am

    Looks nice but:
    filament AC should be twisted all the way and kept as close to the chassies as possible, avoiding
    especially points/circuits where signal exists. This is to keep hum down.


    cci1492

    Posts : 13
    Join date : 2016-05-09
    Age : 55
    Location : Bergen County NJ

    Re: Yet another new guy.....uffa!

    Post by cci1492 on Sat Aug 13, 2016 7:23 am

    peterh wrote:Looks nice but:
    filament AC should be twisted all the way and kept as close to the chassis as possible, avoiding
    especially points/circuits where signal exists.  This is to keep hum down.


    Good point, thank you! It didn't occur to me it was that critical. They are both dead silent regarding any hum, even with the pre-amp volume turned all the way up. The only thing I do notice is with the pre-amp powered off, and if I stick my ear close to either speaker, I hear some RF. But as soon as the pre-amp is turned on, it goes completely away.

    Bob Latino
    Admin

    Posts : 2373
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Yet another new guy.....uffa!

    Post by Bob Latino on Sat Aug 13, 2016 7:48 am

    One of the best stock builds of the VTA M-125's that I have seen. Thank you for sharing the photos of your build. You can tell a lot of time and effort went into the assembly of your two amps.

    As you have found out > If the amps are built properly, they are dead silent.

    How you twist the AC filament wires is not really that critical as long as they are twisted. When you twist two wires, the individual wires of the pair are always at right angles to each other and any interaction between the two wires will be near zero.

    Bob


    LeGrace

    Posts : 49
    Join date : 2016-08-07

    Re: Yet another new guy.....uffa!

    Post by LeGrace on Sat Aug 13, 2016 12:33 pm

    Beautiful workmanship! Makes mine look like a spaghetti jungle. I hope you don't mind, I'd like to print out your pictures to use as a guide for the second one.

    I like your technique of placing insulation over the resistor leads in strategic locations, for example like on the one side of the 4 resistors that connect to the 2 pos lug. Have to admit clearances are tight at the socket side. Also notice you twisted both blue and green wire pairs coming from the output transformer. Is that simply for wire management? Or must these be twisted? In which case I need to double back!

    One thing that has been a challenge is holding onto things. I got to find me some of those "extra hands" gizmos that you have!

    Thanks for posting! What a helpful community!

    cci1492

    Posts : 13
    Join date : 2016-05-09
    Age : 55
    Location : Bergen County NJ

    Re: Yet another new guy.....uffa!

    Post by cci1492 on Sat Aug 13, 2016 6:11 pm

    Thank you gents for the nice comments. It was a lot of fun building them. It reminded me of the old Health Kit days, when me and my dad built 2 25" color TV sets, one for us and one for a friend. What great fun it was to dive into projects like that.

    LeGrace, I twisted the green wires together from the output TA for purely wire management purposes.

    tubes4hifi
    Admin

    Posts : 1261
    Join date : 2008-11-30

    Re: Yet another new guy.....uffa!

    Post by tubes4hifi on Mon Aug 15, 2016 11:39 am

    ALL wires from the power transformer should be twisted since they are carrying AC voltages! twisting AC wires reduces any hum

    vtshopdog

    Posts : 59
    Join date : 2015-07-11
    Location : UT, USA

    Re: Yet another new guy.....uffa!

    Post by vtshopdog on Mon Aug 15, 2016 8:22 pm

    Nice.

    Where did you get the blue flexible "Helping Hands" holding driver board in third photo??
    They look like the work really well

    Peter W.

    Posts : 73
    Join date : 2016-08-07
    Location : Melrose Park, PA

    Re: Yet another new guy.....uffa!

    Post by Peter W. on Tue Aug 16, 2016 8:06 am

    vtshopdog wrote:Nice.

    Where did you get the blue flexible "Helping Hands" holding driver board in third photo??
    They look like the work really well

    https://www.adafruit.com/products/2474?gclid=Cj0KEQjw88q9BRDB5qLcwLXr7_sBEiQAZsGja2xZ6QySGF5UbWuu5jwFmDfuLDaL-IZnTmkOvD0iNF4aAiGj8P8HAQ

    Is one source. And that solder-dispenser is also very handy.

    And, as this is in part a DIY forum, try this:

    http://eleccelerator.com/improved-third-hand-using-coolant-hose/

    cci1492

    Posts : 13
    Join date : 2016-05-09
    Age : 55
    Location : Bergen County NJ

    Re: Yet another new guy.....uffa!

    Post by cci1492 on Tue Aug 16, 2016 8:28 am

    vtshopdog wrote:Nice.

    Where did you get the blue flexible "Helping Hands" holding driver board in third photo??
    They look like the work really well

    I made my own, it's more fun. If you decide to go the DIY route:

    https://www.amazon.com/gp/product/B008O14864/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1

    http://www.ebay.com/itm/TEMCo-1-4-Inch-6-x10-6061-Aluminum-Tooling-Flat-Sheet-Plate-Bar-Mill-Stock-/381296046176?hash=item58c703f060:g:ymcAAOSwCZ5VfxAp

    looks like the price went up on the aluminum, I bought the 6X10 1/2 for $16 shipped....shop around

    http://www.ebay.com/itm/Bosch-HSS-Tap-1-2-20-BT409-1609410376-USA-Bulk-/331022484209?hash=item4d127a42f1:g:bk4AAMXQSbtSMwlO

    Don't buy the tap until you receive the oil pipes. There are 2 threads, tap 1/2-20,and 14Mm-1.50...I goofed and got the 14mm first, but I needed the 1/2. But, it's a tool and I'm sure I'll use the 14 at some point....yeah right! Another good choice (since it's a soft metal) would be Harbor Freight (duck...incoming!). Taps from them is hit and miss, one turns to dust on the first crank (on harder metal) and another is as good as a Hanson or Bosch. I have seen great improvement over the years on the quality of some of their hand tools.

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