Getting percussive with a pinged and processed SSF Stereo Dipole Filter
Updated: Aug 5, 2021
While the SSF Stereo Dipole Filter is an obvious choice for people looking for an expansive amount of sonic options from their filter, I ended up falling in love with it first as a pinged sound source. It can take a few minutes to set the resonance just right on the edge of self-oscillation to get it going and tune each dual pole filter to your liking, but there is surely wonderful harmonic and subtle wave-shaped percussive goodness to be found. I have found it works well with a number of gate and envelope sources into the inputs to achieve the effect, I've been using it in particular with my Make Noise Tempi and Rene 2 modules. Different gate widths and envelopes can sometimes have slightly different effects in the pinging process, so experimentation here is worth considering.
The stereo resonance control makes it much easier to control both sides simultaneously. Depending on how each side is set up considering series vs. parallel, filter topology, and of course tuning of each pole with Frequency and Spread controls, the resonant point can vary considerably. Having the stereo resonance control allows you to precisely tune each side of the Dipole to your liking first with the individual controls, and then have a wider overall control once everything is fine-tuned. Great effects can be had with very subtle modulation into the Stereo Resonance CV input modulated. This also goes for the Stereo Frequency CV in as well. One trick for tuning is to actually take it into full self-oscillation using the Stereo Resonance knob and tune each side together along with their respective spread controls first, then take the macro resonance back down till you get it right at the timbre you are looking for.
And though I love the spirit of Brian Eno's famous advice to never read a manual, this is one module where looking at SSF's notes can really help a lot! The hardest part of this module is understanding the various voltage ranges of the many different knobs, and where knobs should be set as a baseline. Though I imagine the extensive controls can be intimidating to many, it's what makes this module so versatile, and it's arrangement is extremely intuitive once you get your hands on it.
Here's the beginnings of a patch using this approach inspired by a query on the wonderful lines forum, I'll eventually be digging deeper to turn this into a longer piece of music.
Some further patch notes from the video above:
The alternating tuned percussion sounds in the realm of analog tablas, gamelan, and woodblocks is all courtesy of a pinged Dipole, into a Mannequins Three Sisters filter in formant mode, with a touch of stereo spread delay from the WMD/SSF DPLR. The Dipole is in dual LP mode on both sides, but the left side is in serial for a subtle waveshaping as one pole feeds into the other, while the right side is left in parallel for more traditional mallet style sounds. I'm using the combined Dipole AB out into the All input of Three Sisters, while simultaneously bringing in each side of the Dipole separately into the HP and LP inputs of Three Sisters respectively as well. The All output of Three Sisters then goes into the DPLR.
The trashier and more abrasive percussion comes from the same Dipole AB out source used in parallel in the Three Sisters/DPLR chain, but for this voice, it's first mixed with pink noise from a SSF Quantum Rainbow, and then one envelope is used to control that mix. Then it's sent into a Mutable Instruments Rings in the classic Modal mode in mono mode. Last, Rings is sent in stereo into a Typhoon module, an expanded version of Clouds, the legendary granular processor by Mutable Instruments. Using a aux channel on my WMD Performance mixer, I'm also adding some delay on this voice using the Audio Damage Dub Jr. MKII.
I wanted to keep the rhythm reasonably simple to really showcase the sounds, but of course with polyrhythms it can get pretty wild pretty quick with all of the power of what's available with gate sequencing in most of eurorack these days. Using the SSF ZPO as a master LFO and clock source for the system, I set my Tempi to put out a 2 against 3 gate pattern into the X and Y channels of the Rene sequencer, which then each went into a separate channel of the Dipole to create the initial timbre source for both sonic chains. The Rene cartesian channel is used to gate information to trigger the envelope that controls the Dipole/noise mix into Rings, while each channel sends CV information to control pitch to match each respective gate input channel.
Besides the ZPO LFO's, I'm also using the Intellijel Planar 2 to modulate the exponential FM via the 1v/Oct input on the Three Sisters, the SSF URA for random modulation into Rings' brightness and damping, and attenuated noise into Clouds for further percussive timbral fun. More modulation and gates are from mixing the original gates with logic and S&H courtesy of Mutable Instruments Kinks.