Synth Stick

What is this?

Fall 2005

Is this an extremely limited synth with a ribbon controller? Is this the keytar version of a theremin? Is this even an instrument?

It is, at least, a great conversation piece. I can’t take that much credit for it…it’s an adaptation of Tim Escobedo’s Synthstick. Tim used to run a site called FolkUrban that had tons of ideas for instruments and guitar effects that could be made by regular people with parts from hardware stores and Radio Shack. He was a huge influence on me when I first got into this stuff, and inspired countless pedal hackers with his creativity and generosity.

First, there was the theremin. The theremin was invented in 1919 by Russian physicist Lev Sergeyevich Termen (a.k.a. Leon Theremin), thanks to Soviet research on proximity detection. That’s relevant because you don’t actually touch it to play it—there are a couple antennas, and you just wave your arms around it and it makes noise. It’s known for making the eerie sounds in The Day the Earth Stood Still and other 40s and 50s movie soundtracks. A lot of people also think it’s used on The Beach Boys’ “Good Vibrations,” but that’s not a theremin, it’s an Electro-Theremin, which is a completely different instrument. Also called a “Tannerin” after Paul Tanner, who co-developed it with Bob Whitsell in the 50s, an Electro-Theremin has a slider that changes the pitch, and therefore must be touched to be played, but can make sounds similar to a theremin. Tim Escobedo cited both of these as inspirations for the Synthstick, along with a funky little synth that you play with a stylus called a Stylophone.

Construction

The genus of Tim’s design was the use of…VHS tape.

Internally, it’s a simple oscillator that produces a pitch determined by the values of a capacitor and a resistor, but in this case, the resistor is a DIY affair. It turns out that the back of VHS tape will conduct electricity, but not all that well. The more tape the electricity has to go through, the more resistance it encounters. On Tim’s Synthstick, there was a piece of Mylar film (which is a good conductor) placed above a piece of VHS tape, and touching the two together would complete the circuit with a certain resistance (and, therefore, a certain pitch from the oscillator) depending on where along the tape it was touched.

My idea was to substitute a single bass guitar string for the Mylar and package up the whole thing in a vaguely guitar-shaped object that could be worn on a strap and played like a proper rock star. The Synth Stick has a CD4093 Schmitt trigger as the central IC. For some reason, I opted to forego the volume control and instead use only the low pass filter mod, which I think is basically the same thing as a tone control on an electric guitar. In retrospect, it would have been nice to have both so that I could have done volume swells from the instrument itself, but who knows what I was thinking in 2005. The body and neck are made from a piece of 3/4″ poplar from a home improvement store, glued up to be double thick for the body. It does technically have one tuning machine, although it serves no purpose other than to hold the string on one end. A flatwound string would probably chew up the VHS tape less, although it’s still on the original piece—and I do still have the rest of the spool, just in case I ever need to replace it. VHS was already out of style when I first made this.

Sound

Uh, it’s pretty weird. The most impressive thing about it is that it makes noise at all, but I’m not positive that it can deterministically play notes from the western scale. In the following example, there are a few seconds of its natural sound (although it’s going through a guitar amp with some reverb, so it’s not the true direct-in sound) and then I start adding a bunch of effects, including the Potentially Broken Fuzz and the A Weird Amount of Chorus, which are a mess in their own right and capable of becoming their own oscillators. Typically Unfazed and a ton of reverb and delay also make an appearance, and at points, it starts to sound like Throbbing Gristle jamming with whales. Warning: may cause seizures or upset pets.