More music. Inspired by Seefeel's "Spangle". This was mostly performed with Dexed, a computer simulation of the six-operator FM engine from the Yamaha DX7. But the pads in the background are made with a Behringer 112 dual VCO:
Behringer makes a range of Eurorack modules that resemble the Roland System 100m synthesiser of the late 1970s. What was the System 100m? It was essentially the last major modular system of the olden days. It was launched in 1979 and remained on sale until the early 1980s, after which the modular synthesiser market entered a lengthy period of dormancy until being revived by Eurorack in the late 1990s.
On a technological level the 100m benefited from advances in miniaturisation since the heyday of the big Moogs and EMS systems of the early 1970s. The modules tended to pack several features into a compact space, and the system used 3.5mm mini-jacks and one-volt-per-octave tuning, so in theory 100m modules should work with Eurorack albeit that they're physically different sizes.
The 112 is a pair of VCOs in a 16hp case. Each VCO has triangle, saw, and pulse waves, with variable pulse and pulse width modulation (PWM). The buzzy sound in the video above is a result of PWM, the pulse width being modulated by an LFO, which in turn is modulated by a second LFO, so that instead of going wah-wah-wah-wah the pulse width goes wah-wah-wahwahwah-wah-wah-wahwahwah.
Got that? Wah-wah-wahwahwah-wah-wah instead of wah-wah-wah-wah. On a psychoacoustic level the extra level of modulation sounds more interesting. The buzzy sound is also reminiscent of a 1970s organ or strings synthesiser put through a chorus pedal.
The strings pad is just four sawtooth waves layered on top of each other, with pitch modulation, as in the photograph. How does the 112 sound? I imagine if you hooked it up to an oscillator its sawtooth and square waves would look like sawtooths and squares from any other VCO, but to my ears it sounds bright, brash. The oscillators do odd things when they're layered, perhaps because I had them both almost perfectly in tune.
Tuning is awkward. The tuning knob has a big range - over an octave - and it's not very stiff. I found that I almost had to will my hand to rotate slightly to move the knob. Over the course of a few hours the tuning drifted by a tiny amount, although if I hadn't stopped to retune it probably wouldn't have noticed.
And it has sync. I must try that out some day.
