Thursday, 19 March 2009

A sliding pickup

There has been several attempts - by for example Westone and more recently Norton Guitars - to make a pickup that can be moved to the areas of the strings where different antinodes and their corresponding overtones are located. This gives you the sound of a neck pickup, a bridge pickup and everything in between. Though only one at a time.

The T-beam bass and the bracket for the humbucker pickup were too obvious a candidate to not trying something like this. And since I allow myself an impulsive and unstructured approach to my hobbies, I gave it a try.

The pickup bracket has nylon cable clips screwed to it. The clips grip the edge of the T-beam top flange and allows the whole thing to be slid easily along the beam. It was necessary to isolate the pickup from the vibrations of the guitar body (hence the rubber bands and foam padding). If not, the vibration characteristics of the string on the pickup's location would be hardly audible compared to the much stronger body vibrations also received by the pickup. Isolating the pickup also significantly reduced the noise of the nylon clips sliding along the T-beam... nice, because now it is possible to slide the pickup "in-tone" and hear the subtle changes of the timbre of the string.

The bracket and pickup is big and heavy, so one of the next steps will be making a sliding bracket for the much smaller between-strings pickup, which I made earlier. The small pickup should also be better at sensing a small section of the string, where the humbucker due to its length picks up a lot of vibrations - including the unwanted ones. With the big pickup, you can easily hear the difference up and down the strings, but the effect isn't exactly striking. I hope and believe that the small one will do a better job.

I had to rout a channel in the wooden sides for the nylon clips. With everything on, in the afternoon sun, it looks like this:

2 comments:

bertram said...

very interesting... I have myself problems positioning properly my pickups on a non-standard model... - do you know where I could find information about antinodes ?

Alexander Gorm Øst said...

Some time ago I bookmarked some pages that discuss pickup placement. I don't think there is _one_ accepted truth in this regard. My own impression is that the _exact_ placement doesn't matter much since the strings change length (and accordingly the location of antinodes are changed) when you fret them.


Though I didn't find a universal answer, they were useful bookmarks. You might find them interesting as well.
http://acapella.harmony-central.com/showthread.php?t=1433868


http://projectguitar.ibforums.com/index.php?showtopic=15101&mode=linear


http://projectguitar.ibforums.com/index.php?showtopic=28034


http://www.till.com/articles/PickupResponseDemo/index.html


That's the good thing about a sliding pickup: You don't have to make up your mind where to mount it ;-)