The Planck

The Planck

The Planck is a 7 stringed instrument played horizontally by tapping fingers between the frets. The velocity of the finger striking the string causes it to vibrate. The vibrations are translated into an electrical signal via an electromagnetic pickup of unusual construction. The frets are 5/16 inch high off the fretboard. This allows for bending the string by merely applying more pressure downward. Thus, individual strings may be bent when playing a chord producing somewhat similar a sound to a pedal steel guitar. This design also produces sounds similar to a Japanese koto or even a sitar.

Demo 1

Demo 2

Demo 3

Details

The Planck is a standard 25 and 1/2 inches scale length. The actual length of the instrument is 36 inches . It is made from two layers of poplar wood. One layer being thick on the bottom which is where the headstock is carved. The top layer is where the frets, nut, bridge, and tailpiece are placed.

The original pickup had 400 (appr.) winds of 30 gauge wire wrapped around 7 ferrite pole pieces and was made with popscicle sticks from Hobby Lobby. At the bottom of each pole piece is a rare-earth magnet. The strength of the magnets seems to allow for fewer winds around the pole pieces while providing for excellent tone. I'm not an electrical engineer but it seems to work and I'll keep doing it until the men in black suits tell me to stop.
These days the pickups have 1300-1700 windings of 36 gauge magnet wire and the impedence is around 290 Ohms. I've found that I really like the sound they have with these parameters. Most normal single coil guitar pickups have around 6000+ windings of 42 gauge wire (about as thin as one of your head hairs) and much higher impedence.

MakerFaire Experience

I've learned quite a bit since MakerFaire of 2007. I had the good fortune to meet Ken Picou who is a fantastic woodworker. He really helped me make the Planck what I wanted it to be and taught me what tools did what. I also met other people who were design engineers and just plain folk with great ideas and incorporated as many of everyone's ideas as I could. I also made friends with the singing Tesla Coil guys now known as ArcAttack. (Their show must be seen to be fathomed. It will tear your face off and you'll like it that way!) The cool thing about MakerFaire is that you have all of these amazing people doing amazing things who have a wide range of knowledge and experience to share. I have been really blessed by this experience in a lot of ways.

Make Your Own

So below are some instructions which I hope are useful in some way. The Planck instructions are for an old version in which I glued the frets to a carefully hand- sloped fretboard. I hope to put up some better, very detailed instructions on Instructables.com when I can find the time....someday.
These days I machine the frets to be screwed down into fret slots that are very gradually slope cut (each fret being slightly lower than the previous) with a router. If the frets were perfectly level there would be a lot of string buzz so that's why they slope.

Planck Instructions
Pickup Instructions

Funny Angle Picture

email me: seven.seven at ymail dot com