Chord ED15BLS Gets a New Preamp

Amongst the ailments afflicting this Chord ED15BLS acoustic is an EQ-7545R preamp that has just about had it. The owner remembers it working intermittently before he somehow lost the 9V battery holder. In any case, a peek inside the battery compartment gave me the shudders, as the springs and contacts were too badly corroded to be saved. And so, the EQ-7545R, piezo element, and output jack have all been taken off the ED15BLS.

EQ-7545R Preamp

EQ-7545R Output Jack

EQ-7545R, Piezo Element, and Output Jack

    

The replacement preamp is an LC-5. Though not a name brand, the LC-5 works as it should, and that's what matters. There are a few differences, though, between the EQ-7545R and LC-5 in terms of footprint and components. For one, the EQ-7545R features a rather narrow housing with an integrated 9V battery box, and also a standalone 1/4" stereo output jack. However, the LC-5 is much wider, and has a separate unit that houses three components. These components are the 9V battery box, a 1/4" stereo output jack, and an XLR connector.

LC-5 Preamp and Battery Box

As the LC-5 housing is wider, we'll have to cut into the side of the guitar and widen the existing cavity. But that's not all there is to it. To fit the curve of the body, the LC-5 needs to be located to the left of the existing cavity. This, of course, is going to leave us with a gaping hole where the EQ-7545R used to be. How bad is that going to look? Do read on. 

Outline Marked

Perimeter Drilled Out

Here's the New Cavity

The LC-5 now fits as snug as a bug in a rug in its cavity, and I remove the layers of masking tape laid down to protect the finish. And yes, here's that dreaded hole, sticking out like a sore thumb. Should I just leave it be, and maybe call it a side-mounted soundhole? Nope, the owner's not going to go for that. So, I'm planning on using a piece of pickguard material or wood veneer to cover that up, but that can wait till later.

Test-Fitting the LC-5

A Gaping Hole

Let's shift focus to the 9V battery box/output jack combo now. It's basically a rectangular shaped object with slightly rounded corners. Some wood needs to be removed, of course, as all that's there now is a 1/4" hole where the stereo output jack used to be. And so, let's go cut another cavity.

Outline Marked

New Battery Box Cavity

Test-Fitting the Battery Box

Now that the cavities are done, a little vacuuming; and we're ready to install the LC-5 preamp, battery box, and piezo element. Have I forgotten anything? Oh, yes, that gaping hole in the side. You'll be relieved to know that it's now covered with a piece of carefully shaped black pickguard material, and secured in place with a tuner screw.

Piezo Element in Place

Battery Box Installed

Handmade Cover

All Systems Go