Post by chillja on Oct 29, 2023 12:54:27 GMT
Hi, this is a way to patch up a simple «phase locked loop» in Ae. The goal is for creative use, and unusual sounds/modulation. Don’t expect stable pitch tracking or for it to work «correctly», rather have fun with the idea and explore different ways it can be implemented in a patch.
Ingredients:
- “reference” osc (any osc)
- “follower” osc (osc with pitch cv in, preferably analog)
- “Phase comparator” LOGIC module (XOR).
- Slew (might be optional to some degree)
- 1 “reference osc”. This is the osc the other “follower osc” tries to lock phase with. I used a triangle wave from Fmos. Many types of signals (osc, audio, clock/triggers) could be tried out.
- 2 “follower osc”. An oscillator with pitch-cv input. I used ms20 self-resonating filter in this case, as an oscillator. Any oscillator can be tried, but analog ones might give better results.
- “phase comparator”. This is where the phase of both osc’s (“reference” and “follower”) gets compared. It detects the phase difference between both osc’s and produces a phase “correction” cv-signal. For this i use logic module’s XOR function.
- Slew for the phase “correction” signal. Slew can be adjusted for different effects, experiment with tiny ammounts. Also turning off slew on the “down-part” gave more distinct results. And the patch might give interesting results without a slew all togheter.
Patch:
1: “reference” and “follower” osc’s into XOR in.
2: XOR out to SLEW in.
3: SLEW out to “follower” osc pitch-cv in.
4: “follower” osc to mixer/audio out for monitoring.
As you can see the patch itself is pretty simple. I’m no engineer by any means, but i will try to explain how it works. Both osc’s phase information gets compared in the XOR-“phase comparator”. XOR will output a signal when the two inputs are different (aka out of phase). When the signals are in phase with one another (identical phase), the XOR does not output any signal. So the XOR is being used as a “phase comparator”, and outputs a signal based on the phase difference. This signal is the “correction signal” and is sent back to the “follower” osc pitch-cv in. It feeds cv back and tries(! ;D) to correct the pitch and therefore phase of the “follower” osc. The slew can be used to “slow down” this “correction” signal so it does not “over correct” the “follower” osc. Try play with minimal slew adjustments.
There are other things that could be tried out. Attenuating the “correction signal” for example. There is also a way to achieve frequency multiplication by using a clock divider. I have not tried it out yet.
I find the concept very phase-inating and want to explore it more. Tried to explain my understanding of it, and one way to implement within Ae-modular. Will update when i made some recordings. Look up the concept of. PLL (phase locked loops).
Ingredients:
- “reference” osc (any osc)
- “follower” osc (osc with pitch cv in, preferably analog)
- “Phase comparator” LOGIC module (XOR).
- Slew (might be optional to some degree)
- 1 “reference osc”. This is the osc the other “follower osc” tries to lock phase with. I used a triangle wave from Fmos. Many types of signals (osc, audio, clock/triggers) could be tried out.
- 2 “follower osc”. An oscillator with pitch-cv input. I used ms20 self-resonating filter in this case, as an oscillator. Any oscillator can be tried, but analog ones might give better results.
- “phase comparator”. This is where the phase of both osc’s (“reference” and “follower”) gets compared. It detects the phase difference between both osc’s and produces a phase “correction” cv-signal. For this i use logic module’s XOR function.
- Slew for the phase “correction” signal. Slew can be adjusted for different effects, experiment with tiny ammounts. Also turning off slew on the “down-part” gave more distinct results. And the patch might give interesting results without a slew all togheter.
Patch:
1: “reference” and “follower” osc’s into XOR in.
2: XOR out to SLEW in.
3: SLEW out to “follower” osc pitch-cv in.
4: “follower” osc to mixer/audio out for monitoring.
As you can see the patch itself is pretty simple. I’m no engineer by any means, but i will try to explain how it works. Both osc’s phase information gets compared in the XOR-“phase comparator”. XOR will output a signal when the two inputs are different (aka out of phase). When the signals are in phase with one another (identical phase), the XOR does not output any signal. So the XOR is being used as a “phase comparator”, and outputs a signal based on the phase difference. This signal is the “correction signal” and is sent back to the “follower” osc pitch-cv in. It feeds cv back and tries(! ;D) to correct the pitch and therefore phase of the “follower” osc. The slew can be used to “slow down” this “correction” signal so it does not “over correct” the “follower” osc. Try play with minimal slew adjustments.
There are other things that could be tried out. Attenuating the “correction signal” for example. There is also a way to achieve frequency multiplication by using a clock divider. I have not tried it out yet.
I find the concept very phase-inating and want to explore it more. Tried to explain my understanding of it, and one way to implement within Ae-modular. Will update when i made some recordings. Look up the concept of. PLL (phase locked loops).
