BeatBurner (Win; $50; www.beatburner.com) is an addictive VST plug-in that can be used to lightly touch up or completely revamp a loop in real time. BeatBurner passes your loop through a series of processors, each with its own mix control.
You begin with a crossfade between two resonant bandpass filters. This allows you to highlight two frequency zones without squashing the rest of the signal. The signal then flows through a tuned resonator, the pitch of which is set 128 times per loop using a built-in step-sequencer. The pitches of each step can be set in real time using MIDI or drawn in with a mouse.
The resonator is followed by a waveshaper, an unusual trio of multimode filters (each offers lowpass, highpass, and bandpass modes), and three effects: distortion, delay, and flanging. The first filter has an envelope follower that extracts the loop's amplitude envelope and uses it to modulate the filter cutoff in one of four ways. The second filter's cutoff frequency can be modulated with a synced, multi-waveform LFO. The mix is fed into the third filter, which has its own graphically programmed break-point envelope.
Everything in the plug-in can be synced to the host's tempo, and a Randomize function is included. Presets and loops can be selected with MIDI, and you can set the morph time between presets. There are memory locations for 25 presets and 10 loops.
Although you can certainly get radical with BeatBurner, its charm is in its subtlety. You can hear an example of a basic loop with processing that morphs from subtle to severe in the MP3 file "Burned-Beats" at