The Soundmachines NS1nanosynth is an extreme example. It's a multi-disciplinary toy that fuses programming and modular synthesis in a package that encourages breadboarding and hacking as much as it does sound generation. On its fascia are sixteen knobs, a ribbon controller, and no less than 192 pin headers. These headers are divided into three main sections: Arduino headers on the left, an analogue modular synthesis section at the top, and a panel on the right geared towards manipulation of digital signals. For those not familiar with the Arduino, it's basically a microcontroller that allows you to program just about anything you can think of (Laser harp? Check). The Arduino software is easily programmed with the C or C++ coding languages and there's a whole community of users uploading libraries of programs for you to use.
The NS1nanosynth can use MIDI signals to control pitch, CV, and mod wheel parameters, which you can access from your DAW by plugging in the included USB cable. I found the firmware to be slightly buggy—for example, playing a note below C2 occasionally disabled the MIDI port, requiring a reset of the unit or the DAW—but in general it works well. You can also use the Mozzi library to turn the digital section of the NS1 into a synth or effects processor capable of waveshaping, delay, flanging, filtering and much more. For the truly adventurous, you could program your own implementation of any other effect you know of, or create completely new ones.
The modular synthesis area takes up the majority of the NS1's real estate. Left to right, it follows a signal path from the VCO, to the filter, to the amp. Initially, the sub-sections are difficult to pick out, but they're well aligned with their respective pots, so after a while everything starts to become clear. There is only one VCO, but it outputs six different waveforms, including a sub oscillator, pulse width variable pulse wave, and white and pink noise, all of which can be mixed. The tonal waveforms all cover the same pitch range, apart from the sub oscillator, but you can transpose by an octave using the clock divider (though I imagine other intervals could be programmed using the Arduino). There's also a single ADSR envelope generator, which can be patched through two attenuators to various modulation destinations. Each attenuator has two sets of inputs and outputs, and these effectively provide amount controls—controlling CV signals with these parameters is a great way to understand the key role that voltage plays in modular synthesis. There are two sets of LFOs, each with a frequency control and four outputs, namely two triangle and two square waveforms. This design is indicative of how the NS1 makes the most of single components by providing multiple outputs. There are also four mixers, four signal multiplexers, a difference mixer, and a range of CV sources. There's also a sample and hold module, and a ribbon controller that outputs gate and CV information.
To the right side of the unit are buttons, sensor inputs, a few clock dividers, and various logic gates. The logic gates can do interesting things with the square wave LFOs and process audio frequency signals, so achieving effects like digital ring modulation are eminently possible, as per one of the patches in the user manual. The manual and the Soundmachines website provide enough patches to get your head around the whole device, and there's also a GitHub repository that contains a database of patches submitted by other NS1 users. Patching up a basic percussive bass sound gives a solid, earthy tone, but things get really interesting when exploring more esoteric techniques. Feeding the oscillator back into its own pitch CV, for example, results in an FM tone for some pitches, and descends into weird clicking for others. Also, every CV and most audio signals range from 0 to 5V, meaning you can treat one as the other, and the LFOs run up to 160 Hz, so they can act as a source of audio or FM.
The NS1nanosynth is very portable, but I'd say the small size of the pin headers and their labels would make it difficult to patch in a dark live environment. It's most at home in the project studio. However, the NS1nanobridge kit allows you to interface with Eurorack equipment, which would likely make things easier. There's also an NS1 experiment kit that includes another breadboard, integrated circuits and a range of other components, allowing you to delve further into circuit design. Needless to say, this is one for the geeks. To get the most out of it, you either need to have a decent knowledge of programming, electronics, and synthesis upfront, or be prepared for a steep learning curve. The manual covers both synthesis and the separate modules in some detail with informative patches, but if you're learning about these areas as you go, it'll take a while to digest. Whatever your current knowledge level, this is a synth for people who love to learn and get to the bottom of how things work. If that's you, you'll find it a huge amount of fun.
Ease of use: 3.5