Interesting technique for bridgeplate pickup installation

[tadol]

This was new to me - I’ve installed a couple K&K pickups using the double-stick tape and golf tee technique, which worked fine, but this looks much better -

This was an install of an Ultratonic pickup by James May, into a Sexauer guitar. This new pickup uses the same type of transducers as the K&K, or a couple of other brands, but this new pickup requires the installation of 5 separate discs, and the placement isn’t critical, but you have to fit all 5 onto the bridgeplate, so thats alot of wires to be working around inside a sound hole -

The big trick is to pick up at least one pair of very high strength rare earth magnets. James used some app ⅜ dia, and about ¾” long. That does sound very big, but if you lose a grip, a pair of these can cause a bit of injury when they come together unexpectedly. There are multiple sources, and they are not very expensive. The second part is poster mounting putty, I know it by the name blue-tac, but it is readily available as a way to mount posters or photos on walls without making any holes from thumbtacks or the like.

Bruce had predrilled the tailblock of his guitar, and removed the strings and saddle from the bridge. Like a K&K, there are 3 12mm discs that get glued in between each pair of strings, but he adds 1 more 12mm disc just beside the high e to pick up a little more energy from that string, and then he adds a slightly larger disc just below the low E, which is out of phase with the other 4. To place these discs, he puts a small bit of putty onto the magnet end, and adheres it to the bridge top where he wants the disc below. Then he attaches the disc to another magnet with another bit of putty, and reaches into the sound hole and the attraction of the magnets pretty much automatically aligns the disc with the magnet above. Note in the pictures hes marked the magnets poles so he knows which end to putty - remember, opposites attract -

[tadol]

Once hes made sure the disc in going to be in exactly the right position (he had a very nice led light source from Stew Mac, and an inspection mirror), he pulled it out, put on a bit of gel cyanoacrylate, then slipped it back into position. By having more than one set of magnets, he could glue in another disc while the previous was curing. The putty magnet pulls away cleanly from the glued on disc, and the process is repeated until all discs are in place -

His Ultratonic pickup uses 4 smaller discs wired in parallel to create a full signal, and then the 5th, slightly larger disc, is out of phase. These are all fed into a special circuit board he designed, and it has a series of dip switches that you use to determine the amount of out-of-phase signal that is used to cancel out the boominess and mud that is too common with these types of pickups. The net result is an amazingly clean and accurate sounding pickup - and thats without preamp, or other processing. We did not have enough time to try running it thru the Tonedexter, but straight out, and into Bruce’s Humphrey amp, it sounded incredibly good -

This interior picture is of the cutaway James uses to show how the pickup is installed, not Bruces guitar - ;-)

[tadol]

The final step in the install is setting the dip switch for optimal bass roll-off and clarity - James demonstrated how it could be done with a meter and tone generator, but it could also be done by ear, which might actually be preferable as the preferred tone will be somewhat dependent on the amp you use - there was considerable difference between the small class D solid state amp and the all tube Humphrey, and Bruce was planning on spending more time listening to the differences and setting it by his ear, rather than by the voltage reading -

All in all, it left me very confident to install one of these in one of my guitars myself - so I bought one, and will report back in a few weeks when we return from vacation!

[redir]

Yeah that is very cool. Magnets are great for all kinds of things. On a side note, I really like the cutout shape on that guitar.

[Shuksan]

Cool technique. Thanks for posting that.

[James May]

Tad, thanks very much for documenting this. It was fun to do it in front of a group.

I know Bruce is very particular and has a great ear, so it was affirming to see how pleased he was with the result. I'm confident you'll be pleased as well when you install yours.

[Bruce Sexauer]

I was paying so much attention to what James was doing that I didn’t notice Tad taking pictures! Quite a good job, Tad!!!

I have now played the guitar some, and it truly does sound great direct into the Humphrey, no preamp required. The ability to modify the tonal balance with the 12 little switches inside was originally intimidating to me, but James’s demonstration demystified the process completely, turning it from a consideration into a true asset.

[keithandstef]

I have nothing constructive to contribute, but I use to manage a cardiac cath lab and had the lead tech help me install a K&K using the mobile c-arm in the lab. It's like moving x-ray. You could see through the top and also see the bridge and braces show-up "whiter". I envisioned in my head it would work well. It was so funny that it did. perfect placement. So go get yourself a $2M cath lab!

[James May]

Originally Posted by keithandstef

I have nothing constructive to contribute, but I use to manage a cardiac cath lab and had the lead tech help me install a K&K using the mobile c-arm in the lab. It's like moving x-ray. You could see through the top and also see the bridge and braces show-up "whiter". I envisioned in my head it would work well. It was so funny that it did. perfect placement. So go get yourself a $2M cath lab!

This is very cool! If you see any of these on eBay for cheap let us know