Gibson GA-9 closet find

Discussion in 'Amp Central Station' started by King Fan, Jul 11, 2019.

  1. muscmp

    muscmp Tele-Afflicted

    Posts:
    1,332
    Joined:
    Jul 1, 2008
    Location:
    california
    that's the early br-9. i have a later 53 as well as a later 58 ga9

    play music!
     
  2. muscmp

    muscmp Tele-Afflicted

    Posts:
    1,332
    Joined:
    Jul 1, 2008
    Location:
    california
    i would tenderly clean it up and leave it original. my 2 cents. great amp right in between my br9 and ga9.

    play music!
     
    King Fan likes this.
  3. King Fan

    King Fan Friend of Leo's Ad Free Member

    Posts:
    3,892
    Joined:
    Jan 1, 2013
    Location:
    Salt Lake City
    Thanks. I'm starting to think you're right -- the grill cloth is no more beat up than the rest of the exterior, and unless you could find an exact duplicate, you'd be altering a 60+-year-old music artifact.
     
  4. corliss1

    corliss1 Friend of Leo's Platinum Supporter

    Posts:
    3,314
    Joined:
    Sep 13, 2008
    Location:
    Lansing, MI
    Yeah, I wouldn't tweak anything non-electrical on it for sure.
     
    King Fan likes this.
  5. King Fan

    King Fan Friend of Leo's Ad Free Member

    Posts:
    3,892
    Joined:
    Jan 1, 2013
    Location:
    Salt Lake City
    OK, wiser heads will prevail. Thank you, gentlemen.

    The electrical may be challenging enough. The only thing we did yesterday was check the fuse -- and someone had put in 15A in place of the called-for 2A. Hope that's not a warning sign.
     
    muscmp likes this.
  6. corliss1

    corliss1 Friend of Leo's Platinum Supporter

    Posts:
    3,314
    Joined:
    Sep 13, 2008
    Location:
    Lansing, MI
    Sweet! I pulled a 30A out of a Mesa last week. Nothing was cooked, thankfully.
     
  7. King Fan

    King Fan Friend of Leo's Ad Free Member

    Posts:
    3,892
    Joined:
    Jan 1, 2013
    Location:
    Salt Lake City
    Now for the important stuff: Help me overthink the simple process of replacing 5 caps.

    Question 1. Firecracker 10/10 with an F&T 20uF alongside as per @corliss1 *or* mount 3 separate F&Ts on tag strips? The firecracker is more vintage in style, and looks simple and elegant as corliss did it, but the current firecracker with it's ?silver and red visuals might be a bit much. Function-wise maybe much the same? Pretend the second image has F&Ts in it.

    ga9 restored.jpg

    Filter tag strips.png

    Question 2 (sensitivity warning: may be too cutesy for some viewers). Anybody here core out the old paper caps and stuff the new caps inside? I've seen it done on high-end restorations and it looks kinda cool or cute (you decide). I'd be especially tempted on the 20uF paper caps, but I have even seen folks stuff filter caps inside the old cardboard tube.

    upload_2019-7-12_9-48-6.png
     
  8. corliss1

    corliss1 Friend of Leo's Platinum Supporter

    Posts:
    3,314
    Joined:
    Sep 13, 2008
    Location:
    Lansing, MI
    Personally, I'm fine with either of these options. I do secretly like the look of the old caps when they've been restuffed, but it is extra work. Some people here completely freak out when you mention that for some reason.

    The terminal strip is also a good option and you could use the mounting hole there as a ground point, should you choose.
     
    King Fan likes this.
  9. theprofessor

    theprofessor Friend of Leo's

    Posts:
    4,365
    Joined:
    Aug 8, 2016
    Location:
    Chattanooga, TN
    I suppose a lot of this is about how one thinks about form and function, and the relation between the two. It is a matter of taste.

    My approach would be to buy the firecracker and install it and simply to replace any other parts with high-quality new ones, without worrying about encasing them in old forms. Straightforward. Done. As for the red firecracker, no one's gonna be looking inside there, anyway, and to me, neatness is more important than color. You can do the firecracker neat, no problem.
     
    King Fan likes this.
  10. King Fan

    King Fan Friend of Leo's Ad Free Member

    Posts:
    3,892
    Joined:
    Jan 1, 2013
    Location:
    Salt Lake City
    All excellent points. The re-stuffing thing is mostly done for really high-end restorations, which this isn't. Pros: It would be fun (at least for the small paper caps -- stuffing filter caps in the cardboard tube seems like work), and I'd learn something (ding ding ding). Cons: It might look fake or weird to some people, and if this amp went back into general circulation folks might even assume it needed re-capping. Woah.

    The form v. function thing is really fun to play with. Yep, this is an old amp with outsides that any normal human would think were beat and shabby, and as the Professor says, 'no one's gonna be looking inside there.' OTOH I know how it looks -- and on my own amps I'm the one who cares.

    But since I'm doing this for a buddy, and the final vote is up to him, I'm off the hook. :D
     
    theprofessor and corliss1 like this.
  11. keithb7

    keithb7 Friend of Leo's

    Age:
    48
    Posts:
    4,653
    Joined:
    Jan 9, 2010
    Location:
    Western Canada
    I’ve stuffed more caps than turkeys....Hey know your strengths and capitalize on them. I’m a lousy chef. I can cook tubes that’s about it.

    This old cap tube reads 47th week of 1958.

    EDBF2C40-C518-4F08-980D-F5D1A2C4B079.jpeg
     
  12. D'tar

    D'tar Friend of Leo's

    Posts:
    2,135
    Joined:
    Jan 11, 2013
    Location:
    WNY
    For the looks restuffing the bypass caps no problem. Fitting three caps inside that firecracker... forgettaboutit... they do have the multisection 10-10 like corlis used and a single 20 same style.

    His was my very first cap job ever

    20190712_165454.jpg
     
    King Fan likes this.
  13. Crashbelt

    Crashbelt Tele-Meister

    Posts:
    441
    Joined:
    Mar 15, 2017
    Location:
    Cambridge England
    Great find GA9s come up often.

    I love 50s Gibson amps - usually great players after the inevitable issues are sorted out.
    20180617_130258_001.jpg
    Mine are GA5 GA8 GA18T GA77. They all get used. Good luck with the GA9.
     
    D'tar and King Fan like this.
  14. King Fan

    King Fan Friend of Leo's Ad Free Member

    Posts:
    3,892
    Joined:
    Jan 1, 2013
    Location:
    Salt Lake City
    Yeah, good, one of my role models does it. Not nerdy then. :)

    I admit I'd like to try it just for the pure fun of it. My daughter is an archaeology conservator -- most of her grad school courses focused on *ethical v. aesthetic* issues, like do you polish up the corroded Saxon helmet, or display it in its 'honest' state. This amp doesn't have that kind of importance, but I still kind of like the balancing act.


    Yeah, fitting F&Ts in the tube isn't happening. I love your first cap job. What was it?

    Wow, those are beauties. You're gonna give us all a bad case of "GA- GAS." :D
     
    theprofessor likes this.
  15. powerwagonjohn

    powerwagonjohn Tele-Meister

    Posts:
    367
    Joined:
    Apr 30, 2013
    Location:
    minnesota
    If I was doing the work myself I would probably re-stuff the old caps. If I am paying my tech. not likely.
    thanks John
     
    King Fan likes this.
  16. King Fan

    King Fan Friend of Leo's Ad Free Member

    Posts:
    3,892
    Joined:
    Jan 1, 2013
    Location:
    Salt Lake City
    LOL, I was thinking about how to trace the PTP wiring and something made me stop and look back. Why?

    Check the pic of the amp serviced by @corliss1 .

    ga9 restored.jpg

    Now check the schematic.

    ga9 schematic copy.png

    Check the pic of *this* amp. What's wrong with this picture?

    IMG_2443.jpg

    Hint: They all have 8 pins and a keyway...
     
  17. D'tar

    D'tar Friend of Leo's

    Posts:
    2,135
    Joined:
    Jan 11, 2013
    Location:
    WNY
    Not sure... But either you have a mixed pair of 6v6 or the rectifier is in the wrong socket?


    1960 GA-5 Skylark, she is Lovely!!!

    I meant to get a better photo over the weekend :(

    [​IMG][​IMG]
     
  18. D'tar

    D'tar Friend of Leo's

    Posts:
    2,135
    Joined:
    Jan 11, 2013
    Location:
    WNY
    By the way, looking at that multi cap... It looks huge in the photo. Maybe you could fit some of the mojo filter caps in there. They appear quite compact. Might like to look closely at the dimensions in the spec sheet if you can find one. My work filter has my hands tied at the moment.
     
  19. King Fan

    King Fan Friend of Leo's Ad Free Member

    Posts:
    3,892
    Joined:
    Jan 1, 2013
    Location:
    Salt Lake City
    You got it, the rectifier was shifted over a couple of slots next to the preamp. At least the brown base made it clear it was a different tube. It's too easy to swap a 5Y3 for a 6V6 if they're both, say, black RCAs. And if you do, your amp doesn't function right. But don't ask me how I know.

    You're right, the 6V6s don't match, but they both look of an age. Hmmm, I'm just guessing that electronic matching may not be such a big deal here where they run in parallel.

    She sure is. Great sounding amps too, I'm told.

    You're right, it is big, but I'm not sure it's big enough for 3 filter caps. I'm using F&Ts. You could easily fit the 10/10 firecracker in there, but it'd be a lot of work given you'd still have to piggyback a 20 outside. I'm thinking 3 shiny new F&Ts might look pretty nice if I can put 'em in tidily.
     
  20. theprofessor

    theprofessor Friend of Leo's

    Posts:
    4,365
    Joined:
    Aug 8, 2016
    Location:
    Chattanooga, TN
    I can tell you the "right" answer on that one -- leave it the heck alone! :) As someone whose expertise occasionally makes me a dabbler in ancient Syro-Palestinian archaeology, I am ever astounded to think of how much data has been lost by attempting to clean things in any other than the most mind-numbing way (which is why I can't suffer archaeology: all moving slower than a sloth and dusting with chip-brushes)!
     
    King Fan and D'tar like 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.