Acoustic Electric Bridge

[zonie]

Hi. New here and I have a question.

 

I wasn't sure where to post this but because it deals with the electronic area of my guitar I think this is the correct forum?

 

I have just bought a Epiphone PR5E acoustic/electric guitar and as with most new guitars the strings are a bit high above the neck.

In the past, I have cut down the notches in the necks end block (the frog?) to lower the string height and of course adjusted the bridge down so that there is no buzz and all of the strings clear the next higher frets. No problems with my Epi Special or my Epi Dot.

 

My PR5E however does not have any provision for adjusting the bridge which comes without any string notches in it.

 

I would take my knife file and add some notches to the white plastic (?) bridge which protrudes above the adjacent wood about 1/8 inch to lower the height of the strings but I am concerned about damaging the pressure pickup that creates the electronic sounds of the strings and the guitar top.

 

Has anyone on this site successfully made this alteration or does anyone here know if I am risking damage to the pickup by making this change?

 

Any information (even a guess) will be appreciated.

Thanks: Jim

[carverman]

By "frog", you are referring to what the guitar industry calls a nut. Your guitar has an under bridge

piezo pickup hooked up to Equalizer preamp. The piece of plastic in the bridge is called the saddle.

Depending on the model, it can be plastic or bone or some other reasonably hard material.

 

The saddle sits in a slot on the wooden bridge and contacts the piezo pickup underneath on some kind of plate

that the piezo is secured to. Normally cutting down a plastic saddle is not a problem as the saddle just

lifts out of the slot and it can be filed and shaved to bring the action down.

 

I would not cut grooves on the saddle, that is fine for the nut, but grooves in a saddle that has bridge

pins can cause buzzing problems. As well, there has to be a bit of a string angle between the pin

hole and the saddle.

 

Be careful trimming a non adjustable saddle, cut it down too much and you could end up with poor intonation

and it may not stay in tune.

[zonie]

Thank you for the informative response.

 

I have ordered a set of Elixir Extra Light Polyweb Acoustic Guitar Strings which should be here tomorrow.

Before installing them I will check out the saddle to see if it is easily removable. If it is, I may try removing about .020- .030 of its height by sanding the top while duplicating its profile. I intend to go down to 600 grit paper and then polish out the sanding marks.

 

Then again, I may try the new lighter guage strings without altering the saddle. That change in itself may be enough to keep me happy.

 

Thanks again

Jim

[TWANG]

I sand down the bottom of the bridge saddle..

with the saddle in place.. use a pencil to draw a line along it's length on both sides.

that tells you where it was in the bridge in the first place..

an easy way is to put sandpaper on a flat surface... sand the bottom of the saddle

put in back in the bridge.. judging how far you've gone and need to go by looking at the line.

 

you don't wanna do it while it's on the piezo so I agree with carver for two reasons.. notches are harder and pressure may not be so good for it.

 

TWANG

[Ricochet]

I would lightly sand the top of the bridgesaddle down.

Don't remove the saddle and sand the underside, you'll risk damaging the piezo removing the saddle. And since a piezo converts force from string pressure into signal, sanding the underside of the saddle is a delicate and risky task. Any unevenness and your piezo will work less efficient. You'll end up with a very undesirable uneven tonal and/or volume balance.

 

You could slightly notch the saddle(you want the strings to stay in place). But don't cut deep slots like you would on the nut.

Don't put the notch over the saddle, but on the (back-)side where the strings bend down to the body or saddlepins.

[carverman]

Lots of good advice on sanding bridge saddles. Generally speaking, (from my past experience working

with Kalamazoo made Epiphones, Gibsons as well as other flat tops), the saddle is a very tight

fit in it's slot ...but it can be removed if it's done very carefully.

Flattops in the late 60s didn't come with a piezo pickup transducer underneath the bridge,

so it wasn't as critical for saddle accuracy and fit. The transducer picks up string vibrations

along the entire length of the saddle. I don't know what brand of piezo pickup Epiphone are

using in the PR5E, but here is a brief description of the Fishman type..

 

"Fishman transducers are rigid, thin transducers that fit under an existing saddle (but a new saddle will probably be necessary due to the added height, unless the saddle slot is routed deeper). Their new "Acoustic Matrix" system combines the pickup with an onboard battery-powered preamp, and is reportedly significantly superior to their earlier models."

 

You need to be sure of what type your guitar has, before removing any saddle equipped with a piezo pickup.

The piezo contact can be a thin rod sitting directly underneath the saddle in the bridge saddle slot..or it can be a transducer attached to the bridge plate underneath the acoustic bridge.

 

Sanding the underside of the saddle is one way of trimming the string action on a standard bridge,

like the Gibson J45/Epiphone Texan, BUT you have to be very careful to ensure sanding pressure is even along

the bottom side of the saddle. Otherwise it could end up being (possibly) sanded too much at the ends

of the underside of the saddle,making the saddle "crowned" in the middle.

This would reduce the string energy transfer to the piezo, which relies on good mechanical contact all

along the underside of the saddle.

 

One option is to sand across the top of the saddle, but then you have to be careful about

the profile of the top. crowned with a string angle machined on the backside like Richochet

mentions. The other thing is that on most saddles, the bass side will be raised higher

than the treble side,so even though there is a pronounced 12" radius (matching the Gibson

style fingerboards), the bass side will be higher due to the thickness of the strings..so

it is not "flat" across either.

 

Trimming a saddle is as critical as adjusting a nut, because the saddle and bridge is the only

place that transfers string energy to the acoustic top.

[zonie]

Lots of good information. I thank you all.

 

This PPR5E (Ebony finish) uses a E-Sonic system (not the E2 stereo) which uses a "Nanoflex" pickup with "7 highly sensitive and ultra responsive layers of sensor material..."

 

After reading all of the comments, including the ones which point out the potential for damaging the pickup I may just live with what I have for now. Kinda modifying the old saying into, "If it ain't broken (too badly), don't fix it!.

Again, my thanks

Jim