Crawls Backward (When Alarmed)

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Gretsch G5120 Upgrades: TV Jones Pickups, New Wiring Harness and Compton Bridge (Pt. 2)

I've had some recent projects (the Gretsch soprano ukulele and now the Hickok 288X) that seemed to be never ending.  However, this one went fast, which was nice.

Most archtop guitars use a 'floating' bridge - that is, a hardwood base that carries the actual bridge saddle.  The 5120 is no exception - it has a rosewood base and a tune-o-matic style bridge.  But notice how the base doesn't exactly follow the contour of the arched top.   The green arrow shows the gap between the top of the guitar and the base of the bridge.  What this means in practice is that not all the vibrations from the strings via the bridge are being transferred to the top.

And on an archtop, this is an important part of the tone we're losing by not having full contact to the top.

 So I'm going to sand the bottom of the bridge to better fit the contour of the top.  I tape down a piece of 180 grit paper to the top, and with the bridge in the approximate area where it will sit when strung, I move the bridge back and forth in a direction parallel to the strings.

This takes a while, but we wind up with a closer fit to the top curve.

Here's the newly sanded bridge base.  Much closer fit.  I could probably take a bit more off the ends - maybe when I change strings I'll do some fine tuning.

Gretsch also makes an ebony bridge base - I'm toying with the idea of getting on of those.  I think ebony might look better than rosewood - and it's harder also.  

I tried to be careful with the finish on the top of the guitar, but in sanding the bridge, the paper shifted a couple of times and put some light scratches on the top.

So I take my machine polisher to it - scratches gone.  And next time, tape it down more.

Dag that thing is glossy!

The holes for the controls need to be reamed out just a tad to take the new pots and switch.  And yes, the top is plywood...er....laminate.  The originals were too - only high-end archtops have solid carved tops.

Now to put the new wiring harness and pickups in.
Now, you may have been wondering how in the world we get the pots in there.  I've seen folks do this with string tied to the controls and using that to pull the controls through.

But the good folks at TV Jones, who must do this a lot, devised this clever method of using plastic tubing.  Put one end on the pot shaft, and the other end through a hole and pull it through.

I sprung for the "wiring harness install kit" - $6 worth of tubing and a dowel for the output jack.  I probably could have scrounged these at the hardware store, but these are the exact sizes needed, so it was worth the money.  As we'll see going forward, this is a must for this installation.
All posts related to this project:

Part One - Removing original pickups
Part Two (this one) - Fitting bridge base and start of wiring
Part Three - Installing TV Jones pickups
Part Four - Finished!

 
 
 
 

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