Wave Splicer And Phase-Locked Clock Source

• Phase-locked loop
• Synchronizes to an external audio input in a delightfully savage manner
• Three possible frequency ranges
• Three choices of phase comparator, each with distinct character
• Sawtooth output
• Patchable phase comparator/CV loop (works well with King Slender slew limiter)

• Exponential VCO response with external CV input

• Comparator

• Two inputs with attenuator (normaled to PLL output)
• High speed, sharp edges

• "Defeat" input interrupts the control of the Analog Switch

• 1:2 Analog Switch

• Low resistance
• Latched operation: a rising edge at the control input toggles from one input to the other
• Inputs are normaled to DC voltage and have attenuverters.

All three sections of the module are normaled together to affect the greatest possible amount of timbral hostility without patchcords.

THE DESTABILIZER is three utility modules in one, normalled together to aid the generation of obnoxious timbre. A simple phase-locked loop is on the bottom, feeding into the central hi-speed comparator section, whose output finally arrives at a latching analog switch. The signal normals are carefully chosen to operate as a single instrument without intervening patch cables.

THE PLL

To get started, patch an audio signal into the “VCO IN” input. Listen to the signal at the “OUT” jack whilst manipulating the controls.
The Phase-locked loop consists of a simple voltage-controlled oscillator, a phase comparator, and an input for an external signal. In its default, unfiltered state, this circuit produces jittery, unpredictable synchronizations to the input signal, resulting in utterly deranged audio output. The main output is a sort of sawtooth wave that is derived by buffering the PLL device’s integrator. To recover the square wave that is typical of a PLL oscillator output, take the output from the COMPARATOR section of the module.

The two switches of the PLL determine the lock behavior. Experiment to find a setting that reliably tracks your VCO input, if you’re into that kind of thing. Pure square waves work best for accurate frequency following, but the true character of the PLL shines through when spurious components of the inputnwaveform interrupt the loop’s attempt to derive a coherent frequency.

The RANGE switch in combination with the CV INPUT and LARGE KNOB selects a base frequency for the internal VCO. The settings of the switch are, from the bottom up, LOW, HIGH, MEDIUM. HINT: The LOW frequency setting is useful when using higher frequency VCO input. The oscillator will not attempt to lock to the high frequency, but it will still oscillate at lower clock rates, so that you may use the upper sections of the module at control rates.

The PC TYPE switch selects the phase comparator circuit to be used in the loop.

Phase Comparator 1 is a simple XOR circuit. In the context of Oscillator Destabilization, it provides rich, full sync tones and is likely to lock onto strong signal harmonics.

Phase Comparator 2 is a digital memory network. It is the most reactive to changes in the input waveform, making screaming leaps from one sonic regime to another in stereotypical PLL style.

Phase Comparator 3 is a sequential phase detector. It usually makes thin, jittery, unstable noises, but can exhibit a surprising aptitude to lock onto signals out of the reach of the other PC types.

The PC OUT and LINEAR IN jacks can be used to patch other processors into the PLL network. The PC outputs a waveform whose duty cycle represents the phase difference of the internal oscillator and external audio input. When filtered and put back into the LINEAR input, it corrects the frequency of the VCO to lock on to the external input frequency, or some harmonic thereof. The slew limiter on the KING SLENDER module was especially designed for this operation, but any other low-frequency filter will produce interesting results. Processing the signal in other ways will result in additional mayhem.

THE COMPARATOR

This is a high-speed comparator with two attenuated inputs. The first input is normalled to the sawtooth output of the PLL section. The second input is normalled to a DC offset, and runs through an attenuverter to act as a threshold (THD) control. Turn up the small attenuator and adjust the orange THD knob while listening to the comparator OUT to hear a pulse wave derived from the PLL saw. Patch a modulation signal into the THD input for a PWM effect. Patch your own external signals into the two inputs to freely use the submodule as a comparator.

THE ANALOG SWITCH

This is a high-quality, low-resistance 2-1 analog switch with a latching control input. It has two inputs. It is not bidirectional. The large knobs are attenuverters for the two inputs. They are normalled to DC voltages.

The CTL IN receives a logic signal. It’s normalled to the output of the comparator. It pulses a latch that toggles the selection of either of the switch inputs to be passed to the OUT jack.

The DEFEAT jack in the comparator section interrupts the CTL IN signal when patched. A positive voltage at the jack allows the switching signal to pass onto the latch. By sending an intermittent DEFEAT signal with a high speed CTL input, the defeated state of the switch will “roll the dice” and select the one input that was the active state at the instant that the DEFEAT signal arrived.

If you turn one of the large knobs to full negative and the other to full positive, a clock signal passed to the switch CTL in will produce a square wave output. It would be a suboctave division of what is present at the comparator out. You could also use it to rapidly switch between two DC levels that are passed to a quantizer feeding a VCO, to get the impression of two pitches from a single generator.

Suggested system: one each of Kermit MK3, Multiple Miggs Mk2, King Slender mk2, THE DESTABILIZER.

The “classic” full patch of THE DESTABILIZER takes an input from your VCO and listens to an audio mix of the VCO with the outputs of all three Destabilizer sections. The three input mixer on the KING SLENDER is appropriate for this task. Pass an LFO through MULTIPLE MIGGS MK2’s voltage processor to tickle the threshold input for a PWM effect on the comparator out. The analog switch output is thus a jittery, unstable suboctave. The PLL output itself resembles a sawtooth wave. Once you tune the PLL settings to reasonably follow the input frequency, any changes in frequency modulation or waveform on the input oscillator will cause audio devastation to propagate up the DESTABILIZER chain affecting the various outputs in different ways as the PLL struggles to lock to an identifiable frequency. Use Kermit to provide the external VCO signal as well as modulation waveforms for the PLL oscillator, comparator PWM, and slew limiter time.

NOTES

This module was originally designed in 2013. It had an ill-behaved prototype that made a single appearance at a NAMM show. 12 years later, the circuit has grown a few more inputs and controls, with a much better PCB layout. The design of the module was partially inspired by a conversation with Vladimir Kuzmin about “arpeggio switching” multiple control voltages at high speed to give the impression of multiple pitches from one oscillator. It was also greatly influenced by the BAD SECTOR recording “The Harrow”