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I built and added two MPS units to my modular synthesizer so that I could generate percussion sounds and still have the rest of my synthesizer available for other things. The MPS was a great choice for this application.
The MPS has three signal paths and a built-in mixer to combine them. Each signal path has its own envelope generator wherein the attack is fast and the decay is user-settable.
Signal path #1 (noise) is a noise generator -_ filter -_ VCA. This stage is good for producing snares, cymbals, and a sound that suggests pounding on a sheet of steel. When using the "lock" mode of the MPS, the noise generator/filter produces very nice wind and surf sounds.
Signal path #2 (shell) is two audio oscillators -_ ring modulator --_ VCA. When the oscillators are tuned to low pitch, it produces a deep bass resonance that will shake the place. Yes, it will do the kind of bass that one often hears coming from teenagers' car stereo subwoofers. Besides the deep bass, this signal path does mettallic sounds that include hammers pounding on anvils, a sound that sounds like a kalimba being played with a metal pick, and bells of various pitches.
Signal path #3 (impact) is an oscillator -_ VCA. When swept to a low pitch, the impact really sounds like a primitive drums. It suggests hand-slaps to animal skin drumheads and/or the "thump" of a kick-drum. Though this path has no filter, the sweep control and pitch is so effective that this path really needs no filter.
The mixer allows one to combine the three signal paths for output.
The EGs control the VCA's (Decay) and control the frequency (Sweep). The ring modulator has a number of controls (depth, balance, etc) that offers a wide range of control over the timbre of the ring-modulator.
The internal signal paths are designed to avoid clipping and I built up the gain of the final mixer stage -- simply increase the feedback resistance for the output op-amp.
The MPS is a great module -- fun to build and very musical. As of this writing (April 2010) all the chips are readily available on-line.
Rating:  [5 of 5 Stars!] |
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