North Coast Synthesis have released the MSK 007 Leapfrog VCF. I wonder what befell filters 001 – 006? The MSK 007 is licensed to filter and they say has a sound all of its own.
MSK 007 Leapfrog VCF
North Coast Synthesis point out of their website that there are only a few core filter architectures. There’s the Moog ladder filter and then a two-pole state variable filter and that’s about it. With the MSK 007 they believe they’ve done something new and innovative. They put it like this:
The fifth-order “leapfrog” core topology, with five integrators and multiple feedback loops, originates in scientific work more recent than the 1960s and as far as we know never before available in a modular synth VCF.
Intriguing, isn’t it? It has a very sharp cut-off with a near-elliptical response curve, with “ripple in the passband and nulls in the stopband at frequencies chosen to be musically revelant.” The result is that as you sweep the cut-off you hear harmonics pop into life and wobble before the next one arrives.
What I’m not quite understanding here is that it looks every bit like an oscillator. You have two Tuning knobs labelled Coarse and Fine. There’s a 1v/8ve input, both exponential and linear FM and a VCA. So with what, exactly, do you sweep the cut-off when you don’t have a cut-off to sweep?
Hopefully, this will get into the hands of people who can make videos explaining how it all works. In the meantime, you can enjoy the slightly weird audio demos on the website none of which appear to contain a sweep of anything.
- North Coast Synthesis MSK 007 Leapfrog webpage.