The Jazz Guitar Chord Dictionary
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  1. #1

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    A new Epi jpe style box I acquired is near-perfect in dimensions for me, but has some horrible feedback (worse than nearly any archtop I've played). I've also come to almost prefer the tone of semi-hollows anyway and have thoroughly enjoyed the floating toneblock hollowbody types before.
    I have an assortment of clamps, gouges, various small cutting scraping tools, titebond iii.
    I'm creative enough to come up with something, though that doesn't mean it will be effective...

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    The Jazz Guitar Chord Dictionary
     
  3. #2

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    try inserting a sound post under the bridge area...by connecting the arched top to the back, you are changing the vibrations of the body...if the feedback you are getting is from the body design, and not the pickups (being microphonic) then you should notice a marked difference...without getting too intrusive with your mods

    luck

    cheers

  4. #3

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    Awesome. Thank you so much Nea!

    Quote Originally Posted by neatomic
    try inserting a sound post under the bridge area...by connecting the arched top to the back, you are changing the vibrations of the body...if the feedback you are getting is from the body design, and not the pickups (being microphonic) then you should notice a marked difference...without getting too intrusive with your mods

    luck

    cheers

  5. #4

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    Yup, sound post! I think it will solve 90% of your problems.

    Here’s some inspiration - the sound posts in my guitars:

    ES-330/Casino kit guitar:


    Soundpost in my 1950 ES-125:


    Soundpost inside my ES-175 copy:


    And the best one is the one in my Furch G-1. This guitar was very prone to feedback, but with the sound post it’s gone in ‘normal’ situations:


  6. #5

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    I'd suggest a balsa block or dowel, of a size depending on your own tonal preferences. Balsa does not add much mass, is tonally inert and easy to work with. It is structurally strong. Cedar or Spruce or Port Orford Cedar-really a cypress- would be on my list, too.

    Gibson's Chromyte is nothing more than balsa.

  7. #6

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    i like round sound posts...type of wood??... depends on what you want to do...softer gives some flex...harder keeps it stressed...diameter/size as well...not as straightforward as it may seem! hah..what is?

    cheers

    ps- classic violin style



  8. #7

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    Quote Originally Posted by neatomic
    depends on what you want to do...softer gives some flex...harder keeps it stressed...diameter/size as well...not as straightforward as it may seem! hah..what is?

    cheers
    That is what she said!

  9. #8

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    ^ hah...500 years of luthiery tech reduced to a d#%k joke!

    cheers

  10. #9

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    Seems to have done the trick.
    Help installing a partial center block.-20201015_162052-jpg

  11. #10

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    And? How do you like it?

  12. #11

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    Quote Originally Posted by Little Jay
    And? How do you like it?
    Well it does the job pretty well as far as the feedback issue.
    As for the guitar itself, maybe a different story....
    Slightly off topic:
    Having difficulty getting the sound I'm after. Playing it through my Yamaha G50 112 mk-II and trying to get more Herb Ellis polytone sound but it's really kind of bright, chimy and fender-ish Kenny Burrell (which isn't anything bad either) even with the mids cranked and bass/treble on low.
    I'm hoping my 80s orange Roland Cube 60 (I left at my friend's house for rehearsal purposes (last year!)) will help with that when I get it back.
    Thank you for the helpful pics. I've seen/heard a few of your modifications and they're always cool.

  13. #12

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    Quote Originally Posted by arielcee
    Well it does the job pretty well as far as the feedback issue.
    As for the guitar itself, maybe a different story....
    Slightly off topic:
    Having difficulty getting the sound I'm after. Playing it through my Yamaha G50 112 mk-II and trying to get more Herb Ellis polytone sound but it's really kind of bright, chimy and fender-ish Kenny Burrell (which isn't anything bad either) even with the mids cranked and bass/treble on low.
    I'm hoping my 80s orange Roland Cube 60 (I left at my friend's house for rehearsal purposes (last year!)) will help with that when I get it back.
    Thank you for the helpful pics. I've seen/heard a few of your modifications and they're always cool.
    Thanks ;-)

    It's an everlasting ongoing tone quest... so many variables in the chain from pick to speaker... but I am starting to discover some ways to steer the sound in the direction I want....

  14. #13

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    ^ its bright and chimey, because you killed too much tone out of top and back...too big a block or too tight a fit...all it takes is a little round sound post to connect from top and back..that will kill feedback vibrations without killing tone..as long as top and back are connected...

    a big heavy block..and maybe too tight..will kill a lot of essential vibrating i.e. tone

    cheers

  15. #14

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    Quote Originally Posted by neatomic;[URL="tel:1068648"
    1068648[/URL]]^ its bright and chimey, because you killed too much tone out of top and back...too big a block or too tight a fit...all it takes is a little round sound post to connect from top and back..that will kill feedback vibrations without killing tone..as long as top and back are connected...

    a big heavy block..and maybe too tight..will kill a lot of essential vibrating i.e. tone

    cheers
    it would be interesting to have a jazz box
    with an externally controllable length sound post under the floating bridge ....

    then one could find the sweet spot

    ive no idea how this might be physically done tho
    (answers on the back of an envelope)
    (or post em here !)

  16. #15

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    Quote Originally Posted by neatomic
    ^ its bright and chimey, because you killed too much tone out of top and back...too big a block or too tight a fit...all it takes is a little round sound post to connect from top and back..that will kill feedback vibrations without killing tone..as long as top and back are connected...

    a big heavy block..and maybe too tight..will kill a lot of essential vibrating i.e. tone

    cheers
    That is a good point I had not considered it yet, but now that I’m thinking about it: the best results with sound posts I have in guitars with no bracings in them! (Including my ES-125; it has lost it’s bracings at some point in it’s life.)

    I did do a sound post in my Furch that does has bracings, but that sound post is small with little wood surface touching the top and back. I didn’t notice that guitar sounding brighter after installing the sound post.

    So to TS: did the guitar get brighter after installing the sound post or was it already bright before?
    Last edited by Little Jay; 10-19-2020 at 10:37 AM.