Frequently Asked Questions

Can I change the tuning?

No- but that is the point. Do you ask this question about a gamelan or a piano? You are always welcome to pop it open and mod the capacitors, but I don't recommend it. An easier mod it to take the sandrode pads, that have little holes in them, and insert little wires in there, break it out to a breadboard, and play with connecting various passive components such as resistor, potentiometer, capacitor, diode and even inductors between various nodes. Remember you bend pitches simply by touching the sandrodes.

Can mine be all walnut?

No. I choose wood species early in the instrument making process, based on their relevance to the instrument. I always work with local woods. At the time of this writing, early 2015, I have a large stock of sycamore, catalpa, mulberry and sassafras. Sassafras is in my humble opinion, the premier wood for synthesizers, because it sounds open and dry, smells of sasparilla and root beer, and finally, because it has "sass." Sycamore is a little bit heavier and duller, but it is the traditional wood for violin backs. Catalpa is dry like sassafras, related to that wonderful zither-wood pawlonia, and dark almost like walnut. The Tocante instruments are solar chargers, so they will sit in the sun a lot. For this reason, I add a photo-active wood such as mulberry, that goes very dark, almost black, over time in the sun.

What is the scale?

Technically it is a segment of the undertone series consisting of the following degrees: 165, 150, 136, 110, 100, 94, 75, 68, 66, 50, 47, 44, 34, 33, 30, 23.5, 22, 20, 15.5, 15, 13.6, 11, 10, and 9.4. Clusters of three use a simple law of parallel and series capacitors to achieve octaves that fill in other scale values. The tuning also involves precision factors for the components, making each instrument unique.

What are the three flavors?

They are the three primal schematics for transistor oscillators. Thyris stands for thyristor, used for a sawtooth relaxation oscillator. Bistab is an astable multivibrator using the frequency modified bistable transistor configuration; it makes a square wave. Phashi is a phase shift oscillator that makes a sine wave.

How do they respond differently to touch?

Besides the different timbres, the main difference is how they bend sandrodes.

Bistab features "locking style." if you hold the unbent tone of a high note, that frequency will course through your body and modulate the sandrode of say a lower note. The lower note locks to the undertone series of the higher note, producing the characteristic minor harmonics.
The sandrodes of phashi, when touched, cause it to bend pitch a little bit, and also to go quieter, eventually muting them. This is because you are massaging the frequency and resonance of a filter, and may bring it out of saturation. This is "damping style."
Thyris has a little bit of each, you can sometimes lock it, sometimes damp it, but mostly it is a classic "bending style" with sophisticated spectrum.

How does my friend play the instrument louder?

He probably has moister hands. Try using some lotion, or in a pinch, saliva. I have become very aware of my hand moistness. Usually it is not a problem, but there are times when it becomes acutely dry, such as in cold weather. The lucky thing about performance is it usually makes you sweat, giving a clear and loud Tocante tone. Simply warming up on the instrument, holding it a bit, will accumulate moisture between your fingers and it.

Why is phashi quieter than bistab?

Because a sine wave has much less harmonic content than a square wave, it sounds quieter even though it has the same peak-to-peak amplitude. Musically, this is a voicing issue- phashi is for quieter passages and bistab for fanfares. Like on a pipe organ, a trumpet is loud and a violin is quiet.

What is the cluster of red lights inside the speaker?

Those red lights are for checking the solar charging operation. They show how much current the circuit is pumping into the batteries. You can see that they get brighter as they face the sun's light more directly.

What is the role of the large golden bar between screwheads?

That whole metallic area is for grounding the fingers- touching it will mute the sound a little bit, and also it should help with ground hum when using a PA.

I am plugged into a PA, how can I peter the ground hum off?

The instrument sounds pristine with its own speaker, but an external connection will reveal the touching body's inductive capacity for alternating current. A big sack of water like the human body will take alternating currents from the environment and manifest them in an external amplifier as a background hum. Note that this tapers off as you play more notes; more connections to the instrument make a stronger signal. Thus remember the ground bars to strengthen your signal- squeeze them during solo passages for quiet but clean notes. For the cleanest amplified sound use an isolating prosthetic, such as a white cotton glove smeared with graphit, or conductive foam. These are relatively impervious to hum because they are dry and insulate from your body. One more option is to use a passive, high impedance DI box with ground lift, thus floating the instrument so that hum has no reference. You see, hum happens whenever there is a strong, clean ground connection.

What is a sandrode?

It is an unbuffered, internal node of an oscillator that has been analyzed and edited to make it safe from damage to the silicon. That said, don't ever touch the instrument to "hot" connection such as the output of another instrument, or amplifier, or more nefarious sources such as high-voltage or high-current power.

What is the power cycle of this instrument?

It can run for between six to ten hours of constant playing depending on how loud (because loudness equates to power consumption). Remember that it only uses power when touched, and sits quietly otherwise with battery automatically off. So you really could play it indefinitely without running out of battery, as long as you let it sit in a sunny window every once in a while. A day of full sunlight should be enough to recharge an empty battery; overcharging may shorten battery life though. Likewise, try to not deplete it completely. The nickel metal hydride batteries are specified for up to a thousand cycles. In a sunlight-starved climate, you could use a twelve volt DC power supply, with 2.1mm tip positive plug to recharge.

Other tips and tricks?

It can be played with materials such as conductive foam or a banana. A secret quick grunge hack is power starving it. Plug a 2.1mm power supply in, but leave it unplugged. This switches the direct ground through a resistor, slaving all sounds to each other and distorting the output. The output jack can also work as an input- give it a signal such as that of a shnth and it will amplify it.