If you're curious about modular synths but all those knobs and wires leave you reluctant to dive in, KarmaFX Synth might be just the way to get your feet wet. Although it doesn't make patching your own sound a no-brainer, it does make it accessible and fun. KarmaFX Synth is a VSTi plug-in for Windows. It's the result of eight years of effort by programmer Kaspar Nielsen. It is donationware, meaning that you can download a free, fully functioning copy from his Web site (www.karmafx.dk). If you find it useful, a donation of $10 or more would be greatly appreciated.
You can create modules at will, drag them to any location on the synth's work surface, and connect them with cables by selecting source modules from drop-down contextual menus on the destination module. For control routings, the contextual menus are attached to knobs and sliders, whereas the audio-input menu is attached to the module's title bar. KarmaFX Synth's user interface incorporates a number of conveniences: collapsible module control panels, optional knob and slider animation in response to modulation, and a global panel with 32 assignable knobs (4 banks of 8). You can route each of the knobs to control multiple module parameters and assign them to external MIDI controllers. The global panel also manages preset loading and saving, and to save space, you can shrink the interface to display only the global panel.
Each synth module — Generator, Filter, Amplifier, Controller, Effect, and Modulator — is actually a placeholder for a class of processors. You use a drop-down menu in the module's title bar to select among processors from its class. For example, a Generator module can house an oscillator, a dual oscillator, a sample player, a noise source, or an external audio input, and a Modulator module can house a step sequencer, an LFO, an envelope generator, an envelope follower, or a MIDI-message generator. That arrangement makes for great flexibility and speed because you can patch together a basic structure and then swap in different processors for different sounds.
To get you started, KarmaFX Synth comes with two banks of 128 presets, conveniently categorized by sound type (see Web Clip 1). The presets sound great and make excellent starting points for your own experiments, which is always the best way to get a handle on do-it-yourself soft synths. So download KarmaFX Synth, call up some presets, and start swapping modules.