On this demo I decided to concentrate on the self-oscillation of the filter, to see if I could create something interesting from that alone. Obviously one use of an oscillating filter is to create kick drum-like sounds, so that is where I started. I also wanted a variety of other textures to come in at various points, but also for everything in the mix to be produced from one recording of the Raging Bull's oscillation alone.

PATCH DETAILS:

1. Firstly, a snappy Maths envelope was set up in order to create the "kick". It was set to trigger on each beat, with a second slower Maths envelope subtly modulating its FALL time.
2. The 4MS Rotating Clock Divider was then used to produce a number of different divisions, which were all fed into an a151 Quad Sequential Switch. This was randomly stepped through, with the resulting rhythm providing triggers for a second envelope - the a171-2 VCS clone.
3. The a171-2 was patched into a VCA containing the output of an e350 wavetable oscillator. The pitch of the e350 was controlled by a random voltage from the a149-1 "Source of Uncertainty", with another of the a149-1's outputs modulating the wavetables.
4. The a171-2's RISE and FALL times were modulated by further a149-1 random voltages, so that they changed from snappy "zaps" to softer "swooshes". As these were applied to the VCA containing the e350's output, the result was an ever-changing series of rhythmic oscillator "FM stabs".
5. The e350 VCA's output was fed into a mixer, along with the Maths "kick" envelope, and the second slower Maths envelope which was brought in to add movement to the low end of the self-oscillation, providing a bendy "bassline" drone.
6. The output of this mixer was fed into the Raging Bull's Cutoff CV input, so that - by the end of all this patching - the filter was modulated by a mix of "kicks", bendy bass drones and e350 "FM stabs".
7. The Raging Bull's output was recorded dry, and also processed by the Modcan Dual Delay, set to "stereo".
8. The Dual Delay's internal Lowpass Filter was modulated by the SUM output of the Vulcan Modulator - and its various Delay time and Feedback CV inputs were modulated by another output from the a149-1.
9. During recording virtually all the available controls were manually tweaked: the levels of the various cutoff modulation sources; the rates of the Maths envelopes (which were pushed into cycling at audio rates towards the end); the Raging Bull's main Cutoff; the Dual Delay's feedback and filter cutoff; ....and probably more things I've forgotten about!


It's all a bit erratic, but was an interesting exercise in seeing how much material can be generated from a self-oscillating filter alone...and also demonstrates how well the filter will FM and respond to CV sources. It will also do a pretty good job at creating a kick drum! Bear in mind that you will need some decent monitoring to even be able to HEAR some of the sub-bass in this recording..