Reply to Thread Bookmark Thread
Posts 1 to 25 of 25
  1. #1

    User Info Menu

    Check out the fit of these braces to the underside of the top. This is one of the P90 equipped 275 guitars that's been sitting in the case - brand new. Just got the back off this morning. Oh boy.

    .Unfortunate top brace fitting in new Gibson 275-2759-jpg
    Unfortunate top brace fitting in new Gibson 275-2757-jpg
    Unfortunate top brace fitting in new Gibson 275-27510-jpg
    Luthier - The Double Bass Workshop

  2.  

    The Jazz Guitar Chord Dictionary
     
  3. #2

    User Info Menu

    Yeah it looks like it's put together a bit too casually for a guitar in it's price range.
    Tone bars are kerfed so they don't have to shape them to exact fit. But then they didn't bother gluing them all the way
    Never play anything that's hard. If it's hard, don't play it. -- Joe Pass

  4. #3

    User Info Menu

    Wow. Looks like the tail block isn't really glued to the top either. Amazing what Gibson can get away with because they're Gibson.

    Just out of curiosity, how did you end up taking the back off a brand new guitar?

  5. #4

    User Info Menu

    I ended up buying this guitar for a pretty reasonable price as a project, thinking I could get in the F holes with clamps and glue the braces back. Not sure what I was thinking as there's big chunks of dried superglue between the ends of the open braces and the top. So I'm the second owner, no warranty at this point and the only way this is going to get fixed is if someone opens it up. Might as well be me. So I used a router to cut most of the binding off, took the rest off by hand then got a knife around the joint. That wasn't bad but the neck block was a bit tougher. As has been pointed out the tailblock was making little contact with the back, but there's good contact everywhere else. Maybe I'll glue an extension on the short tailblock and chalk fit it in. The kerfed lining is pretty much intact so after the braces are replaced with nice fitting ones I'm going to try and leave the kerfed lining alone without much cleanup that may alter the fit, and try to glue the back on in the same exact position it was. The 275's with the p90's seem to be priced at around $3500, crazy money for this level of quality control IMO although the rest of it looks ok.
    Unfortunate top brace fitting in new Gibson 275-2755-jpg
    Unfortunate top brace fitting in new Gibson 275-2754-jpg
    Unfortunate top brace fitting in new Gibson 275-2752-jpg
    Last edited by vejesse; 08-02-2019 at 11:46 AM.
    Luthier - The Double Bass Workshop

  6. #5

    User Info Menu

    Looks like you've done really nice, clean work so far. It should be a rock animal when you're done. Add $500 to whatever Gibson's charging for 'em (don't you wish?). That's a laminate top, right? Funny that they use curly maple veneer on the inside of the top, but not the bottom where you can see it.

  7. #6
    That restores my faith at buying new gibsons, specially unseen..

  8. #7

    User Info Menu

    It is like sausages and burger patties; love them but don't ever try to find out how they're made.

    Now that I know I can't unknow. Puts a dampener on my enthusiasm. It will be a far better guitar once you're done with fitting your own tonebars to the top.

    That's pretty crazy putting curly maple veneer on the underside where it cannot be seen than on the back where it can be seen. And you are still paying for it.
    Last edited by Jabberwocky; 07-22-2019 at 03:30 AM. Reason: I hate this Autocorrect shirt!!!
    Great Deals with Great Folks: max52 (Guild-Benedetto Artist Award); prickards (Ribbecke GC Halfling); Cincy2 (Comins Concert)

  9. #8

    User Info Menu

    ...The builders may not even know the difference between the top and the bottom or the inside and outside.

  10. #9

    User Info Menu

    ...because the guitar ain't worth much. This is beyond embarrassing. It looks like they're not even trying. This needs to be shared widely to warn the fools out there that Gibson is wholly uncommitted to making a good instrument.

    You should send the link to this forum thread to the president of Gibson. Hah! They should pay you the price of the guitar to kill the thread for the damage it could do to their reputation. Good luck with your improvement effort. I guarantee that the guitar will not be worse than before.

    Thanks for posting.

  11. #10

    User Info Menu

    Omfg... this is really upsetting..... my €250 Ibanez looked waaaay better inside!

    Here's what you get for $3200 less:





    Here's the only little flaw I could discover. Some squeeze-out of the glue.


    :: Jazz, Funk, Soul & Boogaloo: My group ::
    ::::::: Listen to Hip Jazz a Go Go! :::::::
    :: Jazz, Soul, Blues: Eva & The Tracies :::

  12. #11

    User Info Menu

    Mirror exam on my ES-275 looks fine. But I got it new and checked it out thoroughly right away. I learned to do that by experience. You've documented the possible shoddy workmanship elegantly with your pics. Thanks.

    This is really shameful workmanship.
    MG

  13. #12

    User Info Menu

    Quote Originally Posted by vejesse View Post
    Check out the fit of these braces to the underside of the top. This is one of the P90 equipped 275 guitars that's been sitting in the case - brand new. Just got the back off this morning. Oh boy.

    .
    Unfortunate top brace fitting in new Gibson 275-27510-jpg
    Only a Gibson is good enough ....

    man what a guitar !

  14. #13

    User Info Menu

    Any archtop builders care to critique the bracing scheme? Towards the lower end I was able to get a brace tap tone very close to the same note as compared to right next to the brace tapping the top. Closer to the bridge it's about a whole step lower (went too far?), and it's hard to discern by the neck block. By the bridge the height is a bit over 1/2" and it's 3/16" at the lower block, a bit taller than 1/4" at the neck block. I left the height a bit higher by the pickups for structural purposes. Being this is a plywood guitar I don't know if the bracing height will affect the performance of the guitar nearly as much as it would with a carved guitar. But with a nice chalk fitted quartersawn brace compared to crappy kerfed brace, why not?
    Attached Images Attached Images Unfortunate top brace fitting in new Gibson 275-img_0669-jpg Unfortunate top brace fitting in new Gibson 275-img_0668-jpg Unfortunate top brace fitting in new Gibson 275-img_0670-jpg Unfortunate top brace fitting in new Gibson 275-img_0673-jpg Unfortunate top brace fitting in new Gibson 275-img_0674-jpg 
    Last edited by vejesse; 08-10-2019 at 05:21 PM.
    Luthier - The Double Bass Workshop

  15. #14

    User Info Menu

    Wow! I love the pics.
    MG

  16. #15

    User Info Menu

    Nice job fitting the new braces. I particularly like the tapering below the bridge region. This will lower the frequency in that area and impart a nice bass response.

  17. #16

    User Info Menu

    Goid job! Probably will turn out to be a mighty fine guitar - can’t go wrong with P90s in a (thinline) hollowbody!

    :: Jazz, Funk, Soul & Boogaloo: My group ::
    ::::::: Listen to Hip Jazz a Go Go! :::::::
    :: Jazz, Soul, Blues: Eva & The Tracies :::

  18. #17

    User Info Menu

    Quote Originally Posted by vejesse View Post
    Any archtop builders care to critique the bracing scheme?
    Since I'm building from scratch, I don't often stop and tap a top after it's on the rim. Not that it's right or wrong, but I make those decisions before the plate is attached to the rim. From an experienced gut feeling, I like what you've done. When compared to the the Gibson braces, your's are tapered more. Because your braces are not kerfed and fit properly, the final stiffness may be similar to the stock braces but your's will be lighter and that's good. I guess your brace blanks are similar to the Gibson, possibly .3" wide and .5" tall and that's a reasonable starting size because it's a smaller body. I don't think you've gone too far. You've left lots of stiffness between the bridge and the neck block, similar to the Gibson, but possibly loosend up the between the bridge and the tail block and that seems reasonable unless your trying to make it work as a Rock guitar.
    Barry Grzebik - Grez Guitars
    www.grezguitars.com

  19. #18

    User Info Menu

    Thanks for taking the time to give me some feedback Barry. The braces are 0.425 wide" and they are vertical grain Engelmann spruce. That spruce is pretty soft, maybe sikta would have been better but I ended up with a bunch of 7/16" Engelmann spruce guitar bracing stock. I don't have much experience building guitars but I have installed many upright bass - bass bars, and they seem to perform a similar function. With those as a starting point at least I like to tap the bar, then tap the top right alongside the bar, thinning the bar until notes are the same. If the bass bar looks too big I'll go further then, maybe ending up one whole step lower. I'm not sure if the tapping thing has any real magic, but at least you're not working blind.

    I remember that the Gibson 275 I had earlier seemed like it didn't have a lot of bass response, but the highs didn't seem that great either. I wanted at least try to improve the lows a bit by thinning the lower end of the braces.
    Last edited by vejesse; 08-12-2019 at 03:10 PM.
    Luthier - The Double Bass Workshop

  20. #19

    User Info Menu

    Quote Originally Posted by vejesse View Post
    Any archtop builders care to critique the bracing scheme? Towards the lower end I was able to get a brace tap tone very close to the same note as compared to right next to the brace tapping the top. Closer to the bridge it's about a whole step lower (went too far?), and it's hard to discern by the neck block. By the bridge the height is a bit over 1/2" and it's 3/16" at the lower block, a bit taller than 1/4" at the neck block. I left the height a bit higher by the pickups for structural purposes. Being this is a plywood guitar I don't know if the bracing height will affect the performance of the guitar nearly as much as it would with a carved guitar. But with a nice chalk fitted quartersawn brace compared to crappy kerfed brace, why not?

    Keep on replacing crappily glued kerfed braces by nice chalk fitted and tapered braces!

    Just one thought: Gibson and other manufacturers (like Roger in old Germany) used resp. still use quite simple rectangular bars (cross-section). This is desirable from the cost-cutting POV. It's also ok from the functional POV (stability) on mainly electric laminated thin hollowbody archtop guitars. It may even be ok for some carved full-hollow-bodies - but it's not the end of the road!

    Your slight tapering of the braces is a good start for going further. Just have a look on the shape of the bass bar of some fine master cellos; the old masters found the shape empirically during centuries. Much later their work was approved by Jakob Steiner's theorem. Steiner's area moment of inertia calculations are still the foundation of determining the cross-sections of beams in architecture and engineering - valid also for our archtop tonebars! For many archtop guitar makers this seems still to be an alien concept; hopefully this will change in the future!

    Excellent guitar makers (like the one my last avatar - now deleted for possible German patent law requirements - stood for) use(d) the old masters' and Steiner's insights for their work. So, for really fine tonebars (stiffness/weight relation) we'd expect a much stronger tapering, a height of at least 1", combined with a slimmer width … Steiner said it all.


    No commenting here on "brace tap tones", and other stuff that I consider to be widely esoteric, though now (by means of my guitar restoring and production engineer friend who has gathered about 15,000 features and exact measure points on the guitars my avator was pointing to) the procedure could be told how a master maker handled the fitting and selection of tonebars to the tops, and other approaches like the so neglected neck modes. Unfortunately, due to recent and hardly predictable developments with this maker's work in Germany, I doubt the public will get to know exact results in the near future.
    Last edited by Ol' Fret; 08-12-2019 at 09:45 AM.

  21. #20

    User Info Menu

    That's rather wide, not that it's wrong, but I am a little more in the tall/thin camp. I don't know that I would thin them further with out being there to feel/hear what the top is doing, but you might taper the top to what in the link below is called "parabolic shape". This removes a lot of mass from the brace while changing the stiffness very little.

    http://ultimate-guitar-building.com/...ceprofiles.jpg
    Barry Grzebik - Grez Guitars
    www.grezguitars.com

  22. #21

    User Info Menu

    Yes, a tall and thin parabolic tonebar profile would be ideal!
    Ok, let's not be more papal than the pope, time is money! Something like approximate parabolic profiles can be prefabricated and would be desirable in any serial production.

    Unfortunate top brace fitting in new Gibson 275-guitar-brace-profiles-approximately-parabolic-jpg

  23. #22

    User Info Menu

    Time to move on.
    Attached Images Attached Images Unfortunate top brace fitting in new Gibson 275-img_06811-jpg Unfortunate top brace fitting in new Gibson 275-img_06821-jpg 
    Luthier - The Double Bass Workshop

  24. #23

    User Info Menu

    It went from being an authentic piece of junk to looking like it’s going to be a sweet player. At least it didn’t end up under the dozer treads.

    This is is the reason why I hate buying acoustic guitars sight unseen. My Godin is the only time I’ve done it because I knew I had 14 days, no questions asked.
    Redeemed, Husband, Father, Veteran. Thankful for all four!

    I play a customized Godin 5th Avenue, Córdoba GK Studio, and a Hamer Korina. I also play a Kala uBass on occasion

  25. #24

    User Info Menu

    Gibson needs to take some lessons from Eastman and work up to Eastman standards.

  26. #25

    User Info Menu

    As a novice fellow bracer, I appreciate the cool thread! Fine work.