Company: Analogue Systems
When it comes to modern modular synthesizers, there are few options: The A-100 system from Doepfer has some quirky, fun modules; the Concussor system from Analogue Solutions offers a rather intriguing concept of modules that emulate vintage Roland drum machines; and then there's the RS Integrator from Analogue Systems. Boasting feature rich modules housed in a wooden casing, it's the more serious choice for the modular synthesizer connoisseur.
One of the first things you notice about the RS Integrator is that all the knobs are colour coded to help you figure out just what you're controlling: white for audio signals, red for envelopes, grey for control voltages, blue for frequencies and clocks, green for wave shapes, yellow for resonance, slew rates and pans, and orange for everything else. The patch cords also match this colour scheme, although following it is by no means necessary, and indeed one of the main advantages of a modular synthesizer is that any output can be connected to any input, regardless of its intended purpose. Still, this little touch can be very helpful.
The RS-95 VCO
The voltage controlled oscillator is the starting point of most analogue synthesizers' patches, and the RS Integrator's VCO provides a good example of the rich set of features their modules offer: not only can you change the duty cycle of its pulse wave output, as you'd expect, but you can similarly adjust another output from a sawtooth waveform, through a triangle waveform all the way to being a ramp waveform. A sync input is also offered, which resets the waveform back to its beginning state whenever it's activated, causing even more possibilities for evolving timbres.
The RS-110 multimode filter
Continuing the theme of feature rich modules, this filter has five outputs: low pass, high pass, band pass, notch, and a separate output for resonance. The same control voltage input is used to affect the cutoff point of all the filters, and they are applied to the same waveform input, but having four filter types in one unit certainly provides more creative patching possibilities than a standard low pass filter. For those who insist on simplifying their setup, a Moog style low pass filter is also available in the form of the RS-100 module, but endless possibilities are what what modular synthesis is all about and this module will certainly have you headed in the right direction.
While there aren't as many different modules available for the RS Integrator as there are for the A-100, and they often aren't as interesting, they're fulfilling a different niche: These modules provide many more serious features than their main rival's, and all of the basic functions such as oscillating and filtering are performed in ways which provide the musician with many more patching options. In short, this synthesizer is ideal for setting up complex patches, and at the end of the day, that's what modular synthesizers are there for.
Various manuals at http://www.analoguesystems.co.uk/