It's a small sturdy box with a touch sensitive strip - those keys are just printed on it as a guide. The five pots (knobs) are small but turn smoothly and feel solid. Remaining are a volume dial, a three way switch and two 3.5mm ipod size audio jacks, one for aux audio in and one for headphones out, there's also a speaker. In black and white with some curved and some square edges it looks very stylish and a bit retro.
It's a simple analogue synth. A continuous sawtooth tone is generated when you press on the strip - the strip covers an octave and a bit and can be adjusted over a wide range of frequencies using the pitch pot. The tone is fed into a low pass filter, it's cutoff point adjustable with one of the pots and the aggressiveness of it's resonance with another. This filter is also applied to any sound coming in from the aux in, although when using an aux a high filter resonance will lead to hissing.
Lastly there's a low frequency sawtooth oscillator which can be used to affect the filter cutoff point or the tone pitch, the LFO rate and intensity are adjusted with the final two pots - there's a red led that pulses warmly each time the LFO ticks over.
This is my first analogue synth or filter and it's different from any software synth or filter I've used - richer and far more interesting to tweak around. It makes Forbidden Planet style sounds from sonorous sci-fi engine to resonant howling. The LFO also makes for lovely pulsing bass and even kick drum noises.
It isn't a great way to make a melody, it is possible to get the right pitch using a stylus (not included) as the width of the keys is less than half the width of a finger and you must hit the centre of each key. There's no way to fix the LFO to a BPM and it's retriggered each time you press the keyboard strip so don't expect to be able to accurately synchronise it with any external tempo.
If you are adventurous with a soldering iron there are a few people out there who have published guides to allow the unit to be controlled by an external voltage - there's even one to add midi support. I've not tried them.
I loved the kaossilator (
Korg Dynamic Phrase Synthesizer - Yellow Case) and while the monotron isn't quite as engrossing is it small, fun, cheap...ish at 1/2 the price of the kaossilator and of high build quality - I'm finding it a fascinating introduction to analogue synths.