Modern Gretsch Guitars

Bar bridge on semi-hollow Electromatics

1

I've become fond of my semi-hollow Gretsch and want to try putting a bar bridge with some sort of low profile base over the holes where the Tune-O-Matic bridge bolts go. Anyone done this? Any ideas of what works? Thanks!

2

There are numerous ways to go about this, and it’s not at all uncommon. But the details of your instrument dictate the options.

Which guitar do you have? Model number?

3

I have the Bono "red". I'd like a big bar like my 6120.

4

OK, that's a very specific Electromatic. I would be tempted to assume it uses the same Adjusto-matic (with the same post/hole diameters and spacing) as other fixed-bridge Electromatics.

But in my experience, there are two different varieties of fixed-bridge Electros: the Korean-built semi-hollow centerblock line, and the solidbodies from China (and maybe elsewhere). To make matters even more fun, the bridges are "fixed" at different angles in these two series. This doesn't matter to owners who stick with the original adjustable-saddle bridge - but it's a critical deal for those who want to change bridges to anything else.

And to me, making Tru-Arc bridges. We have a series of bridge specifically for the SOLIDbodies. It includes compensation for the unique bridge position on those guitars, and it drops right on the existing posts and makes boogie.

But for the Korean centerblockers, our regular Standard and SerpenTune series usually work - that is, the same bridges we sell for the Japanese Pro Series and American Custom Shop. I say "usually" because in at least one instance the post spacing has been wrong. This drives me nuts.

It LOOKS like the Bono Red conforms to the usual Korean/Electo centerblock spec; that is, posts of 5/32" [4mm] diameter, set 2-29/32" [74mm] center-to-center. If that's the case (and measure carefully, because precision down to at least 1/32 matters), a Tru-Arc or Gretsch rocking bar should work on your existing posts.

I don't know that we've sold a bridge for the Bono Red, so I can't swear that a standard profile Tru-Arc will sit low enough on the adjusting wheels to get the action you want. Usually, though, if an Adjusto-matic sits at the right height, so will a Tru-Arc. But if not, we can do the Low Rider option on the Tru-Arc, which drops the belly of the bridge a bit between the adjusters, and provides more downward adjustability.

The solutions I've suggested so far use your existing posts. In your post, you mention wanting to use a base. So OK, let's explore that.


First, I don't know that doing so would produce a different tone than you'd get by sticking with the fixed posts. There's a logical notion that the broad feet of a wood base make better contact with the top, and/or produce a more complex tone by spreading out the point of contact and thus, via phase relationships across the area of contact, transmit a more complex spectrum of the string's energy to the guitar top. My own sense is that there's something to that - IF the top of the guitar is free to resonate under the bridge area. That is, a bridge on a floating wood base will produce a more complex tone on a hollowbody guitar than a bridge mounted on studs in the same guitar.

But the equation gets different when both bridges are sitting over a block running down the center of the guitar anyway, which is the case on your guitar. So I wouldn't expect much difference in tone or response between mounting the same bridge on the posts, or on a base. Nother words, you'd be going for a floating base either for appearance or positioning (if the fixed posts happen not to be located optimally for best intonation with a bar bridge).

All that taken into account, let's pretend you still want a base. Several scenarios are possible.

1 - The threaded receivers in the top of the guitar (which the posts screw into) FIT FLUSH with the top of the guitar (or lower).
1.1a - Easy deal. Take the posts out, position a base on the top where it needs to be (it will probably cover the hardware), bingo bongo badda bing, put on the bridge, tune up, and play.

2 - The threaded receivers do NOT sit flush; they stick up a little. Oh boy.
2.1a - Can they be screwed in further, to make them flush? I dunno. Maybe. Ask someone else how they'd do that. Hammers and torque come to mind, which is why I don't want to be responsible.
2.1b - Take the receivers out. I don't want to be much more responsible for this than for 2a, but at least I know how I'd go about it. I'd find a bolt that threaded into the receiver, then gently firmly carefully apply just enough but not too much wiggle wiggle force to persuade it to come out. I'd make sure it was completely detached from any finish first, to prevent pulling up an unsightly chip of paint. That might involve a very sharp X-acto knife and better eyesight and hand-eye coordination than I'd want to deploy on someone else's guitar (though I'd try it on my own). I might use pliers or vise-grips.

If you have a good feel for how wood and metal work with each other, so that you know how much pressure/torque/force is appropriate and when it's too much for conditions...OK. (Mine is only so-so.) COVER THE GUITAR TOP WITH MANY THICK SOFT RAGS while you work. Be cognizant that if you "waller" the holes for the receivers out too much while removing them, they won't fit as tightly if you ever want to put them back in. (Which may or may not matter.) • Anyway. If you can get the receivers out, then you proceed as in 1.1a, above. Plop the base on and be happy.

2.2a - So they stick up a little. Maybe you can use that to advantage, without pulling them. This would involve positioning the base EXACTLY where it needs to be, on top of the sticking-up receivers, then deftly using appropriate tools (don't ask me) to carve away partial circles on the bottom of the base which will fit over the sticking-up receivers so that the rest of the base sits flush with the top. (No, I don't know how you'd mark the proper locations on the bottom of the base before deftly carving, either.) But I bet someone could do it.

Leaving all THAT behind, it's possible-to-likely that a base will raise the bridge higher than you want it for best action. Then you get to:
a) get a Low Rider for sure and/or
b) whittle the bottom of a bridge base to lower it.

SO. Depending on dimensions and construction details, bar-bridging your Bono could be as simple as dropping a new bridge on the existing posts. Or it could be harder. But it can definitely be done.

If you want to get deeper into the weeds, contact me at Tru-Arc and we can work through the details.

5

I have a 5420 2015 model (old style headstock) I put a Gretsch Rocking Bar bridge on the stock base posts. I got lucky with a matching radius and a nice fit. But no more rocking feature at all. So maybe thats one point too. It fits but sits flush. I had no problems with tuning or string action (pretty low actually) or buzzing. Tonal improval was remarkable, so I didnt give a damn about the lost bridge rocking feature

6

I have a 5420 2015 model (old style headstock) I put a Gretsch Rocking Bar bridge on the stock base posts. I got lucky with a matching radius and a nice fit. But no more rocking feature at all. So maybe thats one point too. It fits but sits flush. I had no problems with tuning or string action (pretty low actually) or buzzing. Tonal improval was remarkable, so I didnt give a damn about the lost bridge rocking feature

– ChimingBell

Cool. Mind posting a photo? I'm Mr. Curious.

7

If it's not rocking because it binds on the posts - and isn't making good contact with the adjusting wheels - you're probably losing string energy. Tone would be further improved if it fit loosely enough to still rock. (Though "rock" is going too far; a proper rocking bridge more like tips a little back and forth during Bigsbification.)

8

Heres a quick pic. The bridge sits on the adjusting wheels and has good contact. But you see it in the picture - the posts are at the inner side of the bridge's holes and not centered


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