Hi, this is first post in my modular synth patching blog. My system is a small eurorack setup, less than 6U currently: two z3000 vcos, maths, moskwa, moddemix, and the rest is doepfer: A106 xtreme filter, A143-3 quad lfo, A137 wave multiplier, A196 phase-locked loop, A119 ext. in/env follower, A148 s&h, A118 noise/random.
A196 PLL is used in many of my recent patches. So I revisited one of them, where z3000 square wave goes into PLL input 2 (a standard approach), but then PLL vco output goes back into z3000 sync input. For main audio path, z3000 sine goes through xtreme filter used as mix of lp and hp with quite high resonance, and then into moddemix vca as the last point before main output. The vca is opened with maths channel 4 envelope triggered with lfo clock. PLL vco influences the z3000, and this influence is somewhat regulated by pulse width of z3000, so I connected sequential cv from moskwa to z3000 pwm, with moskwa clocked by the same lfo that clocks maths channel 4. This connection doesn't really do much though and I'm not sure if it's mandatory. Then I noticed that turning PLL vco offset knob brings good kind of twist to overall output. So I wanted to emulate this twist with cv automation. For that, I had to break the normalization from PLL low pass to PLL vco: PLL low pass output goes to maths ch2 and maths sum goes back to PLL vco cv input. Then we can mix something into this cv path, and it's A118 random output put through maths channel 1 signal input for slew limiting. By regulating the amount of maths channel 2 (even inverting the signal is possible) and channel 1, we get different PLL vco behavior and thus different influence on z3000. As usual with A196 PLL there's a lot of fun with switching between phase comparator types and between ranges of the vco, and turning the low pass knob.
In the sound example, first and second part are different examples of the patch output. Then, before the third part, I added one extra connection: PLL phase comp out to xtreme filter cv3. Filter resonance was high, so it was creating additional layer of "melody". Then I somehow regulated PLL and z3000 so that the latter displayed no frequency (it was locked or put in lfo range by sync from PLL), while its frequency knob was quite high. It all produced quite convincing random whistling sound. Maybe there's a simpler way of achieving this, but I liked it.
