5G9 - Long time coming - begins

Discussion in 'Shock Brother's DIY Amps' started by Mr Ridesglide, Feb 14, 2020.

  1. Mr Ridesglide

    Mr Ridesglide Friend of Leo's Silver Supporter

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    Yes indeed. I've been threatening for years now, literally years to do this and am going to finally do it. I have what I think are all the parts. I had sent an email a while back to Mr. Mergili about a cabinet, and John told me that he's no longer doing them. Bummed about that, but it was pretty much all I've been waiting for to get started so 10 weeks ago I ordered one from Armadillo and Wil set me up there. He said he was out 10 weeks and sure enough, right at 10 weeks he sent it out. I've not opened the box but I'm sure it's going to be great.
    Okay - yes I drank some kool-aid; got the Mercury Magnetics transformers, including the lower voltage one for the big box Tremolux.
    So for some other details that I'm "sure" of:
    Weber 12A150 - may be too stout and I may come back to using a 12A125, but I'm shooting for headroom here as I'm sure I will be moving the volume knobs to over 8. Later break up will be a good thing.
    The chassis is also from Weber, and it's the large version for say a 5E5A, but it's been screened to include the Tremolo lettering etc.
    I'll make the board from fiberboard from Doug Hoffman. I'll have to see what caps I have, but they'll be F&T for the filter caps and the rest of the electrolytics will be F&T or Sprague probably.
    The coupling caps and "tone" caps likely to be Sozo and/or Orange.
    Yes again I went for mostly the old school carbon comp.
    Here is the layout I'm starting with. I have not double checked values yet, so if anything sticks out as a problem, please feel free to let me know!!!
     

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  2. Mr Ridesglide

    Mr Ridesglide Friend of Leo's Silver Supporter

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    49B6C583-5F37-4611-8598-180BC4BF8696.jpeg Making some progress. Got the fiber board drilled. Installed the eyelets. Dried in the caps and resistors.
    Drilled the holes for transformers and the fiberboard. Checked out the tube sockets for fit. Yup, they are about 1/16” too small. As hard as I had to hit them with a step bit you would think that Weber made this chassis from thee hardest steel ever made. Spent about an hour on that. I think my drill press is about only good enough for fiber board anymore. Had to use Makita power to finish the sockets. image.jpg
     
  3. jsnwhite619

    jsnwhite619 Friend of Leo's

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    Nice job! Step bits in a handheld drill can be brutal. I had a chassis resting on a bucket once so that the steel would fall in the bucket. Smart thinking, right? Well, guess what happened when the step bit got to around the 3/4" part and the chassis wasn't clamped down? I thought I broke my leg because the chassis started spinning like a helicopter blade and gave me a good whack on the shin.

    Board is looking good!

    Sent from my moto g(6) using Tapatalk
     
    Last edited: Feb 22, 2020
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  4. RottenTheCat

    RottenTheCat Tele-Holic

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    Obviously not enough alcohol was applied prior to the injury!

    And seriously nice so far. Keep it up!
     
  5. jsnwhite619

    jsnwhite619 Friend of Leo's

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    The alcohol may be why I thought it was a good idea! ;-). Clamp them to the workbench now!

    Sent from my moto g(6) using Tapatalk
     
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  6. RottenTheCat

    RottenTheCat Tele-Holic

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    Well... beer would give your the "enhanced girth" to properly self clamp, and if she did bust loose, you've already pre-dead'ned the pain!
     
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  7. Lowerleftcoast

    Lowerleftcoast Tele-Holic

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    Yeah. What's up with that. I've got three chassis that need to be drilled for power cord grounding bolts. The chassis are harder than the drill bits.:eek:
     
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  8. RottenTheCat

    RottenTheCat Tele-Holic

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    Lower speed, higher pressure works well on a UniBit, not too slow though, please.

    Waiting for the next episode of construction from Mr. Ridesglide....
     
  9. jsnwhite619

    jsnwhite619 Friend of Leo's

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    Some machine oil or even WD40 will help with drilling.

    Sent from my moto g(6) using Tapatalk
     
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  10. Mr Ridesglide

    Mr Ridesglide Friend of Leo's Silver Supporter

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    A little more progress today. I’ll twist heater wires while watch movie with the family tonite. We instituted a “suggested you be there” Sunday dinner to the kids about 7 months ago. Actually works quite well! They usually show up.
    3A0EC65B-A83D-4EEF-B39B-73C0BEB85F56.jpeg
     

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  11. King Fan

    King Fan Friend of Leo's

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    Ack, MRG, I missed your launch. I'd been putting off my build and waiting for you to lead out. Thanks!!!

    Which sockets are you using that don't fit the Weber chassis? Selfish reason to ask: I also have a Weber chassis in the waiting room.

    FWIW I'll paste your nice layout inline in case it helps those who forget to click on the pdf link.

    5G9 Layout 2 copy.png

    Also though I haven't checked mine against reality, here's what I'd drawn so far. I'm gonna use yours as a comparison to proofread mine.

    5g9 11 09.png

    Did you find a 2M pot for the Speed? I couldn't find one, IIRC, so planned on using a 3M with a bigger resistor, an idea I stole from a 5G9 guru. Without reading through my notes, I suspect it was probably @tubeswell , who knows a ton about these.

    I'm gonna try not to ask a million questions, but I'm impressed and inspired by your build. Thanks for the strong lead!!!
     
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  12. Mr Ridesglide

    Mr Ridesglide Friend of Leo's Silver Supporter

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    Hey King Fan!
    Okay I found a few mistakes in my layout that I have fixed. I’ll put it up later - Some under board wiring errors that appeared when I stretched out my turrets a shade.
    Yes I did find some 2M pots. I ordered 2 I think, so if you don’t find one, let me know.
    Also, decided to do the grounding as worked out by you and Tubeswell. More on that shortly I hope.
    As for the sockets, I’m pretty sure they are the Belton, but will double check later. 1-3/16” is larger than the 1-1/8” I think the chassis was. Grrrr. All good now however.
     
    Last edited: Feb 24, 2020
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  13. Mr Ridesglide

    Mr Ridesglide Friend of Leo's Silver Supporter

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    Okay King Fan -
    Yes the Weber Octal Socket openings were punched at 1-1/8" - 1.125" and indeed my octal sockets are 1-3/16". Novals fit fine.
    5e7 Chassis.png

    Here is my updated layout - and I still need to double/triple check the original schematic/layout to make sure I didn't miss a 820K for an 820 etc.... but I did solder them in - dumb/brave like that; or I can be.
    5G9 Layout 3.png
    I think the grounding is like the one you and Tubeswell passed back and forth. I may try grounding the trem as I had it first, which was from the cathode of V3 to ground bus; with this is that option to utilize should it have what appears to be grounding issues. I'm not sure why, but seems like alot of wire that "could" make a loop. I already took Tubeswell's idea to take the pre-amp filter cap all the way over to near the input jack side of the ground bus. I'm thnking that it is a long wire run... but I also think that it may be best. I have it in a grey color, albeit difficult to see here.
    I only have 10K bias pots - and I've used them before... I just keep forgetting what resistor size works best with the 10K pot.... for some reason I think I have some 43K ones on hand... and I think the only reason I'd have those is because that is what worked before... ???? We will see!
     
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  14. King Fan

    King Fan Friend of Leo's

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    Heh, I can tell we've both been thinking about this for a long time -- overthinking for too long, in my case. How to ground the trem? How to do the bias -- I did read somewhere that a 10k pot should be big enough to tune bias in any amp if the resistors are right.

    And of course the question: What parts will fit the Weber chassis? It's cool that Weber publishes that tech drawing with all the dimensions. But did you say which octal sockets you're actually using? If Beltons, Doug says, "Mounts in a 1.18 inch chassis hole for top or bottom mounting. Can also be mounted in a .99 inch hole for bottom mounting using the small diameter section of the socket."
     
  15. Mr Ridesglide

    Mr Ridesglide Friend of Leo's Silver Supporter

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    Yes. Belton and from Doug. 1.18 is 1-3/16. 1/16 larger than 1-1/8
     
  16. King Fan

    King Fan Friend of Leo's

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    LOL, you're right. I had to think for a second to be sure a 1.125 hole wouldn't fit a 1.18 socket (like, um, why? maybe 125 sounds larger than 18??).

    But have you considered bottom mounting the socket? Or did you already step-drill the stainless? I'm not harping on this, it's just I face the exact same issue. :)
     
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  17. Badside

    Badside Tele-Meister

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    (Nvm, I'm an idiot)
     
    Last edited: Feb 25, 2020
  18. Mr Ridesglide

    Mr Ridesglide Friend of Leo's Silver Supporter

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    The size difference was causing it to rock a little. If it was smaller it would have worked, or lol, larger. They are now in fact drilled and mounted.
     
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  19. FenderLover

    FenderLover Poster Extraordinaire

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    Great work so far!

    Aren't his chassis polished stainless steel? That's gotta be a bear working a chassis like that.
     
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  20. TobyZ28

    TobyZ28 Tele-Meister

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    Subbed to thread, looking forward to watching this build as it progresses. Good luck...!
     
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