Unwanted vibration inside Busker Delta biscuit resonator

[bluesteve9]

I have a Busker Delta biscuit resonator which has developed an unpleasant buzz/vibration inside the body of the guitar when played. The guitar is usually in open G tuning, and the buzz started when I tuned down to standard tuning one key below normal standard (I have heavy MM .015 to .056 strings, and with these strings trying to get it to standard tuning seemed very tight). I believe the cone is held in place by the downward pressure of the strings at the bridge pressing through the bridge and biscuit, and that loosening the strings has allowed unwanted vibration, but now when I tune back to open G I'm still getting some vibration. I attach a couple of pics of the bridge.

Any informed comments or advice would be gratefully received.

Cheers,Steve

Attachments:

[Michael Messer]

The 15 - 56 strings are not causing the problem. They are not heavy, they are medium gauge and they tune to pitch at lower tension than regular strings. The only string that is heavier than standard medium gauge sets is the top .015, and that tunes to standard E with no problems.

I think that for some reason the change of tuning has either unsettled something, or it is a coincidence and unrelated to the change of tuning.

The break angle looks fine, so that is not causing the problem.

If you are sure it is coming from inside the guitar, it could be that one of the mushroom pit props has worked loose, or that maybe the biscuit screw into the top of the cone has worked loose.

These buzzes can be deceiving, it could be a string winding that has come loose, it could be a tuner vibrating, it could be the truss rod vibrating in the neck. It could be the ball ends of the strings under the tailpiece vibrating on the coverplate It could also be a loose coverplate screw.

I haven’t solved your problem, but I have hopefully opened you up to some possibilities.

Ask some questions if you are unsure how to determine where the buzz is coming from

I hope this helps

Shine On
Michael

[pete1951]

Odd sounds from resos are often hard to find. Even though it sounds as if it’s coming from inside it’s good to rule out and outside noises.
Sometimes a strings ball end can just touch the cover plate, usually slackening the string and turning the ball a little will do the trick.
Cover plate screws ,if not tight, can cause a rattle- If you have never used a screwdriver this can be a dangerous manoeuvre. Make sure you have the correct one . This is probably a Phillips 1point not a Pozi 1 point ( there are 2 types of crossheaded screw in common use, they are almost compatible)

Other common things ( probably not your guitar) are machine heads and strap buttons
A loose truss rods can also be a problem, tapping the back of the neck can narrow it down
Good luck
Pete

[bonzo]

Something I've found with rattles is don't test for them with the guitar on its back. The rattles often dissappear in playing position. In your case I don't think this applies, just a general comment. Cover plate nice and tight is a good place to start. 👍🎸🤞

[Michael Messer]

Aug 8, 2023 11:06:48 GMT bonzo said:

Something I've found with rattles is don't test for them with the guitar on its back. The rattles often dissappear in playing position. In your case I don't think this applies, just a general comment. Cover plate nice and tight is a good place to start. 👍🎸🤞

John, When that happens it is usually due to a loose, or not seated correctly mushroom pit-prop. The back of a brass bodied instrument (if built with the correct gauge brass) is very soft and bendy.

Shine On
Michael

[bluesteve9]

Thanks for all your comments, particularly Michael, you've given me a good list of things to check. 

Thanks again,
Steve