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
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
- 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