First Scratch Build(s) - 5e3 and Supro 1624t

Discussion in 'Shock Brother's DIY Amps' started by JeremiahL, Jul 12, 2017.

  1. JeremiahL

    JeremiahL TDPRI Member

    Posts:
    9
    Joined:
    May 6, 2017
    Location:
    Minneapolis, MN
    I just finished up my first scratch build (I did one kit a few months ago). I got the 5e3, and my friend got the Supro (another 5e3, I know).

    The 5e3 has robrob's NFB mod, tube/ss switch, pre-phase-inverter master volume, and "Lead channel" mod. Thanks a million to rob for that, I'm extremely pleased with the results.

    The 1624t is based on the first version of the amp, with 6v6 tubes and a grid-leak-biased input triode on the non-trem channel. I replaced the single tone control with the dual-control from the 4th version of the amp. It also has the rectifier switch.

    Here's some pics of the finished product. I'll post some pics from during the build once I sort through them all.

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    The lighting in my basement isn't great, so I'll probably take a few more pictures of them when I get the chance.
     
    Last edited: Jul 12, 2017
    Il Duce and Snfoilhat like this.
  2. D'tar

    D'tar Friend of Leo's

    Posts:
    2,579
    Joined:
    Jan 11, 2013
    Location:
    WNY
    Congrats! Those look fantastic!
    Welcome to the forum!
    More pics and sound is always welcome.
     
    JeremiahL likes this.
  3. JeremiahL

    JeremiahL TDPRI Member

    Posts:
    9
    Joined:
    May 6, 2017
    Location:
    Minneapolis, MN
    Since the 1624t is such an amazing amp with such little information on it, I figured I'd share my experiences with the build.

    First of all, there are so many versions of the amp with discrepancies between datasheets (and even errors) that it takes some time to sort through them and decide how to approach the amp. This thread was helpful, just beware of the error in the tone control on the Oahu schem: https://www.thegearpage.net/board/index.php?threads/amp-build-thread-supro-1624t-type.1758490/

    We decided to go with version one of the amp, because I was curious about the grid-leak-bias, and we had heard that it got just a little bit angrier than the later versions. (plus we were hoping to get those sweet sweet Jimmy Page tones).

    The stock tremolo really does go from fast to really fast, so I ended up changing a capacitor value to make it slower and choppier, and subbed in a dual gang pot for the speed control to widen the range. Here's a good resource for designing phase-shift oscillators for amp tremolo: http://www.aikenamps.com/index.php/designing-phase-shift-oscillators-for-tremolo-circuits. The tremolo also tends to make a horrible ticking noise, which can be fixed with a 100p cap between the grid and cathode of the tremolo triode.

    The first preamp tube position is very sensitive to the specific tube it's using, so we tried a couple until we found the best. We just used JJ's for now (yeah, sue me) until we can get our hands on some NOS. Also, by some stupid mistake, we had a 12ay7 in the PI position, and it was a very very nice, smooth breakup. Not quite the raunchy supro tone that you get with the stock setup, but it sounded incredible. I'm also not sure how great that is for the amp, so I would do your homework before you tried that.

    The tone knobs seem to work alright, if you don't mind 100% of the tone sweep being in the last 30% of the pot's rotation... I used linear pots because I read that the originals had linear, but I believe Valco switched at some point to audio taper. However, if the first half of the sweep is completely dark, it seems as though I would need reverse audio taper to get a linear sweep. Correct me if I'm wrong.

    I forgot to mention that I also included a switch to jumper the input channels. This feature is really nice when you're plugged into the treble input of either channel, because the jumper lets the bass frequencies through, therefore increasing the volume by a lot. I can include a drawing of how I did the jumper switch with the treble and bass inputs if anyone wants, because it's not quite the same as a 5e3 jumper switch, and there are a couple ways to do it.

    Sorry for the long post, I just wanted to share my findings so there would be more information available on the 1624t. Let me know if you want a schematic or drawing of anything I did.
     
    Il Duce likes this.
  4. JeremiahL

    JeremiahL TDPRI Member

    Posts:
    9
    Joined:
    May 6, 2017
    Location:
    Minneapolis, MN
    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    Please Excuse the messiness of the Supro board. I used a general purpose piece of turret board with turrets already on it, and did some of the layout on the fly, so it wasn't nearly as pretty as it could have been. I also found out that 10 watt resistors are very large....
     
    Il Duce likes this.
  5. boredguy6060

    boredguy6060 Poster Extraordinaire

    Posts:
    5,254
    Joined:
    Mar 28, 2012
    Location:
    Sou Cal
    Nice looking cabinets,
    Sound clips would be very interesting.
    Perhaps you could show how all these mods sound.
    If it sounds anything like it looks, then you've hit the jackpot.
    Love to hear it!
     
  6. JeremiahL

    JeremiahL TDPRI Member

    Posts:
    9
    Joined:
    May 6, 2017
    Location:
    Minneapolis, MN
    Thanks for the compliments! Both amps really do sound great, but I'm pretty busy right now, so it might be a couple weeks before I can set up my nice mic and get sound clips up.
     
    Last edited: Jul 13, 2017
  7. JeremiahL

    JeremiahL TDPRI Member

    Posts:
    9
    Joined:
    May 6, 2017
    Location:
    Minneapolis, MN
    Some gutshots with everything installed:

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    These pictures were taken before I fixed the mistake I made in the Supro (hint, I got a little excited with my ground bus).

    And here are the finished chassis:
    [​IMG]
    Eventually there will be a black stripe on the supro, under the white knobs.
     
    Il Duce likes this.
  8. Il Duce

    Il Duce Tele-Holic

    Age:
    56
    Posts:
    615
    Joined:
    Nov 11, 2013
    Location:
    NYC
    Awesome sauce! I'm building my first amp kit, a Trinity TC15. I'm off to a very slow start as I had to order the transformers after getting the kit and haven't wanted to get too much into it until they arrive, hopefully by the end of this week.

    I'm so stoked on this first build that I'm already considering my next, you guessed it a Supro build! So I'm really excited by your build.

    Here's a teaser until I get some more done,

    20170709_221658.jpg
     
  9. JeremiahL

    JeremiahL TDPRI Member

    Posts:
    9
    Joined:
    May 6, 2017
    Location:
    Minneapolis, MN
    Oh come on, you just had to come in here and show me up with your spectacular board wiring ;). I only hope my next build will look like that. If you're looking for a good ~15 watt supro, I'd definitely recommend the 1624t, otherwise the 1690t is supposed to be it's 6L6 big brother.
     
    Il Duce likes this.
  10. Il Duce

    Il Duce Tele-Holic

    Age:
    56
    Posts:
    615
    Joined:
    Nov 11, 2013
    Location:
    NYC
    Really appreciate the compliment, but when I post a pic or two of my heater wiring you'll see my real skill level, functional but not so pretty! Lol
     
    JeremiahL likes this.
  11. JeremiahL

    JeremiahL TDPRI Member

    Posts:
    9
    Joined:
    May 6, 2017
    Location:
    Minneapolis, MN
    We made the cabs out of 1" pine (3/4" actual width). We used a kreg jig for the butt joints.

    The baffle screws into the top and bottom boards on the front of the cab, and isn't attached to the sides (I think that's called a floating baffle?)

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
    Il Duce likes this.
  12. JeremiahL

    JeremiahL TDPRI Member

    Posts:
    9
    Joined:
    May 6, 2017
    Location:
    Minneapolis, MN
    Now onto the staining. We weren't to happy with the first color we tried (dark walnut), because it ended up looking too light and yellow for what we wanted, as you can see:

    [​IMG]

    I believe this is because we sanded too much. Our final grit, recommended by a friend, was 320, which is quite fine, and I think didn't allow the stain to soak in very much.

    To remedy this, we tried a second coat, this time with red mahogany color. It turned out much better:

    [​IMG]

    We then did two coats of spar varnish, which I think worked really well.

    I'll get more finished pics up eventually, as well as a sound clip.
     
    Il Duce likes this.
  13. robrob

    robrob Poster Extraordinaire Ad Free Member

    Posts:
    7,784
    Joined:
    Dec 29, 2012
    Location:
    United States
    Those are really nice amps--chassis and cabs. I love the angled back panels.
     
    JeremiahL likes this.
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.


  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.