End-pin Jack Installation Puzzle....

[Mike Kolb]

So a customer brought me his 1970 D28 and his fresh in-the-box K&K pickup for an installation.  It should be relatively easy, but noooooo....

The problem is that the tail block is too deep for a standard-issue endpin jack.   Hmmm.

I called K&K for any options they might have and was told "we run-across this every now & again with older Martins, and the only fix is to counterbore the tail block an amount that allows the jack to fit, lengthwise". 

Easier said than done, my friends.

I've attempted to squeeze my hand, along with a short 3/4" forstner bit and a flexible shaft inside the box, and the results were predictable... we all won't fit!  

Even if everything fit (which it doesn't) there's the problem if "hitting the hole square" to make the counterbore centered on the existing 1/2" hole.  Yikes. 

Years ago... somewhere on Frets.com, I saw that Frank had a "reverse bore" drill he made from scratch. Of course (a). I can't find it now and (b). it would probably take some skills and equipment that I'm not in possession-of.

It occurred to me that maybe someone manufactures something like that...  ideally it'd be a "kit" with interchangeable bits and perhaps a couple of different-diameter shafts.  Any thoughts from the crew?

[Stephen Morgan]

Mike I'm not sure if these are available anymore but they were well made and I installed many of them. It works by an allen screw at the base of the jack that when tightened from the OUTSIDE pushes the balls into the sides of the endblock. As long as the hole in the endblock was reasonably clean and straight they held well. The other benefit was that it is a 4 conductor jack that allowed 2 different signals, ground and battery shut off. I worked on some of Michael Hedges guitars in the early 90's and these were the solution to his multiple pick-up issues. 

[Mike Kolb]

Good info, Stephen.... they're sure new to me but the theory makes sense. I particularly like that they do the "minimum invasion" insofar as needed to rework whatever existing guitar they're going-into.

The extra conductors don't hurt, either. 

I'll have to keep my eyes open for a source, as it can't hurt to have a couple of extra tricks in the bag for whatever rears it's head down the road.  Thanks again :)

[Paul Verticchio]

Hi Mike.

These piqued my interest too.

I only found a supplier in Sweden(!!) with these in stock. The price is around $65 USD. EMG USA has little to no info on them so I presume they're discontinued. Now I'm kind of wondering 'why?'. It was either a design that didn't hold up (in the long run) for the majority of real-world players OR few players wanted to pay that much for an endpin jack.

Interesting concept. Thanks for the heads-up on the technology, Stephen.  I wish Switchcraft would adopt the multi-point contacts. That design change would be welcomed by players AND tech's. :)

Later on :)