Metasonix RK7 VCO

Stubborn, loud, unruly and abnormal are just a few adjectives to describe Metasonix modules. If you're looking for a precise Thru-Zero oscillator with perfect tracking over five octaves and as pure waveforms as possible, you've come to the wrong place.

Stubborn, loud, unruly and abnormal are just a few adjectives to describe Metasonix modules. If you're looking for a precise Thru-Zero oscillator with perfect tracking over five octaves and as pure waveforms as possible, you've come to the wrong place. Even those who are looking for the typical "warm" sound of tubes (and don't feel a bit stupid when using the term "warm" in an audio context) will not get their money's worth here. We're looking at a proud niche product that is so cleverly designed that it is protected against all kinds of idiocy like reverse polarity, over- and undercharge, and it looks so good that the boss of the industrial cassette label you want to impress with a studio selfie will surely send you a heart at Instagram. Let's move on to the technical and historical facts: Basically the RK7 is a Eurorack version of the legendary TM-3/ S-1000/ R-55 VCO circuit and is based on the two tubes 5696 Thyratron and 5702 Subminiature Pentode. Both are military surplus products used in avionics (electrical and electronic systems in aerospace aircraft). With the exception of the 1930s Trautonium, there is probably no synthesizer based on thyratron tubes. Whole TWO waveforms are available: something sawtooth like and, wait, is that supposed to be a sine? With some brave clipping even square waveforms may be possible. The CV range covers about two octaves (C2-C4). With an octave switch you can switch down to three octaves. So you can also use it as an LFO (if you really have nothing better to do). By the way, there is also a VCA on board! This can also be controlled with bipolar signals like LFOs. The current consumption is 220 mA and 500 mA during the short power-on process (when you turn on your rack).