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    Newbie St-120 Build

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    Digdug

    Posts : 18
    Join date : 2012-10-05

    Newbie St-120 Build

    Post by Digdug on Thu Oct 02, 2014 11:14 am

    Hello All,

    I have an ST-120 and SP12 that I bought pre-built, and a few months ago I bought an ST-120 kit to put together. So far, I've only soldered together a headphone amp. I guess I'm spoiled by the Tubes 4 Hi-Fi equipment, because to my ears, the little headphone amp sounded a bit dissapointing. With this second ST-120 I'll bi-amp my speakers. Even though I bought the kit months ago, I haven't had the time to start on it. I'm getting married this November, (38 years of being single was long enough for me) and preparations for the big day have eaten up most of my time.

    Anyhow, I'll try to post some pictures of the build as I go along. Also, I wanted to take a minute to just sing the praises of the Tubes 4 Hi-Fi equipment. My ST-120 and SP12 are amazing! They've brought the musicians on my LPs into my house, and have improved my sound better than any other components in the signal chain.

    Highly recommended! Hope to post progress reports soon!

    sKiZo

    Posts : 1287
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Newbie St-120 Build

    Post by sKiZo on Thu Oct 02, 2014 1:17 pm

    Let the good times rock 'n roll!

    - DO take your time. First time right is a good thing
    - DO pay close attention to the step by step build instructions provided with the kit. Check off each step as you go along, and it's hard to go wrong. Where it says to solder, do that - where it says not to solder, I highlighted those sections for extra special attention later.
    - DO go through the step by step one more time (at least) after the kit is built. Not uncommon to find a dOH or whoops! in the mix.
    - DO have a good light and magnifier handy. An articulating bench light is your friend here. You'll want to take a real close look at each connection - if it don't look right, do it again.

    Speaking of benches, I wouldn't recommend trying something like this on the kitchen table or in the garage. DO set up a nice workbench where you can set the project aside without worrying about losing anything. Being this close to slipping on the noose ... er ... getting hitched up, it will also be nice to have a handy hideaway already established before the new missus moves in ...

    Nothing fancy in tools required, but I would HIGHLY recommend investing in a good solder station. Cheap pencil irons just don't cut it if you want it right - not enough heat, and they'll go cold after a joint or two. You can get a real nice Weller WES51 station for around $100 that has excellent temp control and recovery. Also get some good solder and tip tinning compound as well as flux paste. I like Cardas Quad (expensive, but hey, I'm worth it) or Kester 60/40 for point to point construction. The flux paste is nice to pre-treat the heavy metal connections for quicker heat transfer and solder flow. The tip tinning is just common sense - do that regularly to keep it clean and hot.

    Oh. And toss the silly sponge they give you for cleaning the tip. A brass cleaner is the way to go.



    That's from MCM Electronics, but most any electronic supply will have them.

    ~~~

    PS ... congrats on the upcoming nut ... er ... nuptials ...

    Digdug

    Posts : 18
    Join date : 2012-10-05

    Re: Newbie St-120 Build

    Post by Digdug on Thu Oct 02, 2014 1:50 pm

    Thanks for the tips! I do need to find one of those brass cleaners. I have a Weller WLC100. Hopefully it'll do the job. I did not know that flux paste existed, honestly. That's how new I am to this. I'll be sure to keep the tip properly tinned.

    Can I get away with using a brass scouring pad until I can get a real brass cleaner?

    MontanaWay

    Posts : 767
    Join date : 2014-02-06
    Age : 58
    Location : Cameron, Montana

    Re: Newbie St-120 Build

    Post by MontanaWay on Thu Oct 02, 2014 2:13 pm

    Digdug wrote:Thanks for the tips!  I do need to find one of those brass cleaners.  I have a Weller WLC100.  Hopefully it'll do the job. I did not know that flux paste existed, honestly.  That's how new I am to this.  I'll be sure to keep the tip properly tinned.  

    Can I get away with using a brass scouring pad until I can get a real brass cleaner?

    you can use any steel wool, although brass is better. I also use the wet sponge pad, using both the sponge and brass cleaner will keep your iron tip and solder joints at their best!
    You've got a good soldering iron already.

    audiobill

    Posts : 271
    Join date : 2014-03-13
    Location : Philadelphia

    Re: Newbie St-120 Build

    Post by audiobill on Fri Oct 03, 2014 3:52 am

    And Always triple check your soldering on pin 5 - bias!

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Newbie St-120 Build

    Post by deepee99 on Fri Oct 03, 2014 1:39 pm

    audiobill wrote:And Always triple check your soldering on pin 5 - bias!

    Yup, and also triple-check the 3-pin bias pot connex on the driver board. I missed one and it drove me nuts 'cuz all the voltages checked out and everything lit just fine. And, as skiz said, a decent soldering iron is a must. Learned that the hard way, too, my el-cheapo was either too hot or too cold. A soldering gun is handy for those multiple connexions.


    Digdug

    Posts : 18
    Join date : 2012-10-05

    Re: Newbie St-120 Build

    Post by Digdug on Fri Oct 03, 2014 5:51 pm

    Thanks for the tips, everyone!

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