solving the weak E string problem.

 Solving the high E string problem on the Acoustasonic Player Tele.

Summary

(AI generated)

The author describes troubleshooting and resolving a significant volume imbalance with the high E string on a Fender Acoustasonic Player Tele, particularly when using the piezo/acoustic voices. Through a series of steps—relocating the piezo cable entry, filling the original hole, leveling the saddle, and adding a thin paper shim under the high E—they successfully increased the string’s output to nearly match the B string, resulting in a guitar now suitable for gigs, playing lead lines and fingerpicking without noticeable volume dropouts.

How I solved the problem

 Of all of the issues I have had with the Player Tele, the low output of the high E string when using the piezo/acoustic voices was the most challenging and frustrating. When I received the guitar nearly two years ago, both the B and E strings were lower volume than the rest – shifting the piezo sensor toward the high E side improved the B string, but the E was still weak. Over the last few weeks, my opinion was that the guitar would not be usable for me at gigs because, as a lead player, having notes drop significantly in volume was not acceptable. Fingerpicking also had challenges, as notes on the high E string were barely audible.

Before diving in to solve the problem, I measured the output of the guitar using my Fluke 87 DMM on Peak Min/Max capture mode (250uS response time) and found that the B string generated peaks of about 50mV on average, and the E string only about 25mV. This is a 6dB difference, and explains why this was so audibly noticeable. While I expected that the thinner E string would generate less output, a two-to-one ratio is not normal.

I made three changes to the guitar to solve the problem, and all three are critical based on my testing (for the most part, I tested each step individually before proceeding to the next). Before doing anything, I tested the piezo to verify that the entire element was working properly and there were no dead spots. The piezo was fully functional.

First, I changed where the piezo element enters the bridge saddle slot. As built, the piezo comes up through the bridge on the high E side, I drilled a new hole (a 3/32” drill bit was a perfect match) on the low E side. This change did two things – it allowed the piezo to easily extend all the way to the high E side in the saddle slot, and flipped the bend in the piezo cable under the low E string. I theorized that not enough of the piezo was under the high E, and the bend was allowing a small gap to exist under the high E, affecting the amount of pressure applied to the piezo (piezos work best when they are under even pressure). 

(new hole at top on the high E side, original hole at bottom on the low E side)

(piezo changed to enter the slot on the Low E side)

This change did not solve the problem by itself, because the original hole was still present at the high E side. This hole meant that part of the piezo was floating over an open space, so no pressure was being applied to it. Second step was to fill in the hole. I used a cylindrical toothpick that happened to also be 3/32” diameter, and did my best to fill in the bevelled slot, gluing the toothpick and filling the cable slot.

(original hole on the High E side. Note also the bevelled slot for the piezo cable. )

This was still not good enough. After some research that indicated that even a fraction of a millimeter gap between the saddle and piezo can negatively affect output, I checked the saddle. While it was flat along its length, across the thickness there was a very slight high ridge from the molding process. I coated the bottom with silver Sharpie and gently sanded it flat with 600 grit sandpaper (on a machined flat surface). I did not test this iteration by itself, instead I decided to add a very thin paper shim (0.07mm thick) of about 5/8” long (yes, mixing units) just under the high E string to take up any remaining air gap, and ensure that there was adequate pressure on the piezo. This total solution worked.

Measuring the output, on average the B string still yielded about 50mV, but the high E string increased to 43mV, only a 1.3dB difference. With harder picking, the E string easily achieved over 50mV. Playing through an amp or PA, there was no discernable difference between the volume of the B and E strings either on lead lines or fingerpicking.

I am now confident that I can use this guitar for gigs; I consider all of the flaws of my guitar to be fixed.