Joy of Synths #35 littleBits CV
Control Voltage with littleBits in this non-musician’s guide to creating sounds for podcasts, videos, and sampling for music using analog synthesizers.
littleBits Audio Instruments
littleBits produces kits aimed at the youth education market. Rather than software development/coding, they focus on hardware development, or how a physical electronic circuit can generate a result. Bits are independent circuits that connect to one another to create simple tasks like turn on a light. From the simple you can build out a multi-function system. They connect by built-in magnets. Hence, a collection of connected circuits, or littleBits.
TONES, TONES, TONES
An instrument is played by a series of actions. You can define an instrument by what you must control in order to play it. For example, a flute requires breath control, mouth control (embeture), and dexterity of one’s hands. Apply this to an electronic instrument - what generates the tone? With littleBits, you have an Oscillator, Noise generator, self-generating Delay, and a self-oscillating Filter that becomes an audible sine wave if you turn the second Peak dial full right. That’s four tone generator options. You can also bring in external sound with a Microphone bit.
If you like blinking lights on your instruments, littleBits allows you to add as many lights as you desire. The only limitation is acquiring the Bits and battery life as the circuits are powered by a 9 volt battery. The more lights, the lower the battery duration. As batteries lose power, static/hum affects the sound. Swap in a fresh 9 volt for clear sound. Alternately, you can buy the USB power bit ($10) that allows you to power the littleBits for extended periods of time.
BUYING LITTLEBITS IN 2025
Reseller sites are the main way to purchase littleBits Kits, which are the best way to get more Bits. Alternately, you can buy new kits and bits from Sphero.com if they are still in stock. littleBits was bought out by Sphero in 2019, so what stock gets replenished is up in the air.
I obsessively purchased kits between 2019 to 2022 from (big secret reveal) ShopGoodwill.com. The big secret is to search by “little bits” as two words in addition to one word. Individual Bits were more available on eBay. I checked the prices and resellers are charging as much as buying littleBits direct from Sphero dot com. Amazon used to be nice as a seller/shipper of littleBits but the prices are much higher than necessary.
PRICE RELATIVITY
The buying of littleBits should be in contrast to a proper synth. I compared a $15 littleBits delay to a $150-$300 delay module and bought a lot of them. Well, they’re not the same. And the start up cost for littleBits may exceed the cost of a semi-modular synth. I’m out of the market for a new releases but I can’t say enough nice things about new and pre-owned Pittsburgh Modular synths like the SV-1, SV-1b, Taiga and Taiga Keyboard. Compare and contrast because a semi-modular synth may be cheaper overall than creating an elaborate littleBits Synth.
littleBits for Control Voltage and Interface
Given that analog synths can be had for under $200, why would anyone want to play with littleBits? Aside from being fun, they are a practical source of control voltage to play and/or modulate a semi-modular synthesizer. They top out at 5Volts so they can be used for V/O pitch inputs, modulation inputs, and a trigger/gate signals for Envelope Generators.
For example, you can take a Pulse bit, which emits a periodic square wave, and a Step Sequencer (Square waves) and use a Mixer bit to emphasize A over B, B over A, and A & B at full right. If you play with the Mixer while recording, you’ll find the percussive beating of the sequencer changing in interesting ways. This blending of voltage creates different wave shapes to modulate a filter, oscillator, amplifier, or whatever other modules/sections that take CV inputs. Alas, you need to get this voltage OUT of littleBits, and for this you have two options: a CV Bit or Proto Bit.
Amassing littleBits may seem like overkill but some of the modules in the Buchla Tiptop Audio line have a lot of CV inputs. This is what makes them interesting and variable. But you need to plug in Control Voltage. littleBits are a great source for sending CV and Trigger signals. The littleBits Oscillator can go as low as unpitched beating frequencies, and in square wave shape it can trigger an envelope generator.
CV BIT VS PROTO BIT FOR MODULAR SYNTHS
littleBits released the $36 CV control voltage bit to allow folks to send and receive control voltage between littleBits and analog synths modules. This will output voltage in 1 V/O or Hz/Oct for Korg synths. If you have non-Korg synths then a more cost effective solution is the $13 Proto Bit, still available directly at Sphero.com
You’ll want to buy 2 to 6 Proto Bits because each CV bit would send or receive control voltage from the littleBits output of the Korg SQ1 step sequencer. I haven’t tested CV Bits to see if it could do both (send/receive) simultaneously, so it stands that you would use one to send and another to receive. A Proto bit can only send OR receive. They are single purpose Bits, so you require two Proto Bits to send two signals from a Sequencer bit: the volts per octave to the right output and trigger gate signal at the top output. At $26 for 2 Proto bits that’s far less than $72 for 2 CV bits.
Since the 4 Step Sequencer bit has 2 outputs, and the Keyboard has 2 outputs, buy Proto Bits in multiples of two, starting with 4 Proto Bits. If you’re focus is on Control Voltage and NOT tones, you don’t need to overspend on the littleBits Korg Synth Kit. Look to the littleBits Electronic Music Inventor Kit.
CONTROLLING WITH VOLTAGE
The littleBits Electronic Music Inventor Kit comes with an updated Sequencer, Keyboard, Oscillator and Speaker. It also includes a proximity sensor, accelerometer, wire, and velcro feet. The velcro is very helpful. A problem with littleBits is transporting them. The magnets connecting the Bits are not so strong as to keep it from pulling apart with movement. Velcro feet helps keep everything connected in place. They work so much better than the snap-in indented plates included in the kit.
PROXIMITY TO VOLTAGE
The proximity sensor allows for more voltage to pass through based on an object’s proximity to the sensor. This object can be your hand or a wand or whatever you decide. If you consider that a keyboard transmits voltage on the basis of 1 volt per octave, you can get close to that control of voltage with a proximity sensor, with the ability to jump octaves based on object position.
Another Bit to play with is the light sensor. This is similar to the proximity sensor (an object moving closer to the sensor blocks light, changing the output) but perhaps has less range of voltage output than the proximity sensor.
EURORACK OPTIONS
Using a proximity sensor or light sensor allows for a new old way to interface with a semi-modular synthesizer. For example, Doepfer makes a Theremin module (A-178 Theremin Control Voltage Source) that features an antennae that transmits 1 v/o pitch and gate information based on your proximity to the antennae. I find the littleBits proximity sensor to be more fun, particularly if you have a Numbers Voltage readout following it to see how much voltage is passing through the proximity sensor. However, the A-178 is about $120 and may be a lower price compared to acquiring new littleBits from Sphero.com. But from my user experience, a proximity sensor followed by a voltage readout is easier to make sense of and play than an antenna.
To clarify, the order would be Power>Proximity Sensor>Numbers Voltage Readout>Proto Bit output. I added an oscillator, delay, filter and speaker so the “instrument” could be played without an analog semi-modular synth.
The upside to littleBits is their low cost relative to Eurorack modules. If you are Arduino-fluent then perhaps those sensors may be more economical. However, littleBits doesn’t require coding or much troubleshooting. They are great hardware building blocks of themselves.
WHAT ABOUT GATES?
Due to low cost, you are not limited to just one proximity sensor. The Doepfer Theremin module outputs v/o and gate signals. You would need two Proto bits and a wire splitter bit to get to the same place.
Some gates are triggered by a change from low to high. This is why an LFO square wave or reverse saw can trigger an Envelope Generator to open the Voltage Controlled Amplifier (VCA). While the Envelope Generator sets the shape of the voltage that controls the loud/quiet over time of the VCA, you only need trigger it with a low to high wave shape to start.
SPLITTERS
littleBits has various splitters, so 1 power supply can split to 3 individual outputs that could have their own sensor and Proto Bit for manipulating 3 items to start- Oscillator V/O, EG, and/or direct to Osc Mod, Filter Mod, or VCA CV.
If you have a Eurorack Multiplier or Headphone Splitter then you can share the same littleBits voltage output with other Eurorack Modules. Again, have two headphone splitters for the CV and Gate outputs. This requires an investment in having more of 1 thing, but that allows for a greater chance of variation. Otherwise just use one sensor and ProtoBit and a headphone splitter if you want everything to be the same and possibly in sync. But again, more control voltage sources equals more fun.
IN CLOSING
As of 3/15/2025, I’m already deeply invested in littleBits so most of 2025 has been dedicated to sorting ways to play semi-Modular synths with the littleBits. It’s better than using analog synths to play littleBits, mostly because a “real” synth’s voltage may range greater than the 5 volts of littleBits.
Next newsletter may land before or after April 1st. Plans are to record an Omnichord and possibly littleBits at the Melrose Center Audio Studio, Orlando, FL. I’m interested in hearing if and how the sound changes running through a Neve 1073LB pre-amp. That’s one value of an Audio Studio- having access to better recording gear in a space that is purpose built for recording. Cheers!
All Contents Copyright Anthony Torres 2025. All rights reserved.