TK Karpluck String patch (Sequential Pro 3 tuned feedback, Karplus Strong) demo

video upload by ToyKeeper

"I'm just noodling with Karplus-Strong synthesis on my Pro 3, using a tiny pluck of noise as an exciter to get the tuned feedback circuit started. Basically everything in this example is coming from the feedback, to demonstrate its expressiveness and range while it self-oscillates and evolves. None of the oscillators were used at all; they're completely off.

Apologies for my sloppy, aimless playing. I mostly just wanted to demonstrate the variety of timbres and textures which can be created this way. I'm barely even doing anything; most of the expressiveness comes out on its own just based on how the patch is played.

Sometimes it sounds like an acoustic guitar. Sometimes it sounds like a cello being bowed. Sometimes it's a big angry growl. Sometimes it's a searing lead. Sometimes just a soft hum. All from a single, surprisingly simple, patch.

To tweak the sound, I mostly just play legato or not, to control when a fresh "pluck" happens versus just adjusting the tuning of the feedback circuit. I also used the mod wheel sometimes to add distortion, used the pitch bend wheel occasionally to dampen and detune the feedback, and occasionally bumped the feedback amount up or down by a single notch to control whether sustained notes would slowly build or slowly fade. Oh, and aftertouch for pitch-linked vibrato.

The feedback seems to be quite temperature sensitive, so the amount must be tweaked a bit each time it's used, and the sound isn't ever quite the same. So I recorded and uploaded the first improvised take, with no attempts to correct anything.

Audio is straight out of the Pro 3, dry. This is what it sounds like without any processing.

To make a patch like this, basically just start with an init patch, turn off the oscillators, route a plucky aux envelope to the noise level, and turn on tuned feedback (amount = ~62 to ~64, tuning = 24). The rest is just performance conveniences, like the mod wheel, aftertouch, pitch wheel... and some delay."