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Get along with VCA!

Dive into the ultimate swiss army knife module

In this Waveguide blogVCAWe will introduce various patches using!

How many VCA modules do you have?Nowadays, there are many digital oscillators that can be used as a single synth with one module, so maybe I don't have a VCA!Some may say that.However, the original function of VCA, "Voltage control of signal output levelThe role can be used for various patchings.VCA is an "army knife module" that can be used for a variety of purposes, as the English says "You can never ever have enough VCA's".

 

VCA components

I / O jack

Modular beginners sometimes say "I don't understand VCA" or "I don't understand the difference from the envelope", which is probably because VCA has one output, but it is called "signal input" or "CV input".Two types of inputIs one of the reasons.As an example of a module that is difficult to understand because there are two types of inputs in the same waySample & holdthere is.

In VCA, "Signal inputThe signal patched to the knob and "CV inputThe size is changed by the voltage patched to "" and output.The basic patch patches audio to the signal input and CV to the CV input, but it can also patch audio to the CV input and CV to the audio signal.However, for convenience, in this blog, the input of the amplified signal is called "signal input", and the input of the signal that controls the amplification factor is called "CV input".

Level knob, attenuator, combo knob

How about the knob-type controls?It is often installedAttenuator,offsetEach knob has the following functions.

  • Attenuator: Knob to attenuate the voltage to the CV input
  • offset: A knob that controls the output signal level when the input CV is 0V. If no CV is input, setting the offset to 0 will increase the output level, and increasing the offset will increase the output level.Manual control knobFunction as

So, in the case of a VCA without an offset knob, is it possible to control the output level without patching the CV?This is not the case, and many VCAs without offset-only knobs supply a constant voltage, such as 5V, internally to the CV input if not patched to the CV input, allowing the attenuator to manually control the output level. ..Because it is a knob whose function is switched by patchingCombo knobIt is also called.However, if it is patched to the CV input, the supply of 5V will be lost, so it is necessary to control only with the CV, so if you want to control the volume with both the CV and the knob at the same time, select the one with an independent offset knob. Please.

Others To the CV that is input depending on the VCAresponseOften there is a control knob that changes the.This will be especially useful if there is no curve adjustment on the envelope side.

VCA is Voltage Controlled "Attenuator"?

In addition to input and output, another reason why VCA is difficult to understand is that many people have the impression that the "function to amplify the signal" is the first because it is pulled by the official name of VCA, Voltage Controlled Amplifier. Can be mentioned.Signal amplification is also possible depending on the VCA module, but VCA also has a maximum amplification factor of 1 (unity gain).In modularThe function of VCA is not to increase the gain, "Of the output signalLevel voltage control"Do" is the most important role. Even if it is not an Amplifier and operates only in the direction of attenuating the signal, it is a VCA if the amount of attenuation can be controlled by voltage.So it would be more appropriate to interpret VCA as "Voltage Controlled Attenuator".

What if I put in a negative CV?

(It's a little advanced content) What happens if you input a negative CV to VCA? If the offset is not 0 and there is sound at CV = 0, it will be negative until the output volume becomes zero. You can add a CV to reduce the volume (see Patch 5. Ducking).However, when the volume becomes 0, any more negative voltage has no effect.The patch 7. Half Wave Rectifier patch described below takes advantage of this effect.

Actually, there is a module similar to VCA that reacts even if you put a negative CV with an offset of 0.that isRing Modulator / Quadrant MultiplierIn this case, if the CV and offset are combined and become negative, the waveform will change.flip upside downTo do.In other words, the voltage to the signal input and the voltage to the CV input include the code.multiplicationIt works to do.It's not an attenuator, it's like an attenuator with voltage control, so if you call a normal VCA a "Voltage Controlled Attenuator", you could call a ring modulator a "Voltage Controlled Attenuator".When VCA puts audio on both inputs, as you do with a ring modulator, it's called Amplitude Modulation (Patch 2).

 

Recommended VCA module

Now that we've reviewed VCA, here's a recommended VCA module for Clockface!I tried to collect by type, such as those with multiple channels and those with particular attention to sound.

Multi-channel VCA

4CH or 6CH VCA.If you allow enough VCA for your system, you can try different patches. Intellijel Quad VCA has high functionality, and Boost switch is convenient in addition to offset and response control. The ALM Busy Tangle Quartet, on the other hand, is compact with simple controls.It also features a mix function.
  • Intellijel Designs Quad VCA

    ¥28,900 (Tax excluded ¥ 26,273)
    Coming Soon
    A 4CH VCA mixer that combines high-quality features and functionality

    MUSICAL FEATURES Quad VCA is a 4CH VCA mixer with 12 high-performance and high-quality VCAs housed in 4HP. The output is a nested mixer, so that the output of each VCA will be mixed with the output of the next channel unless patched. Therefore, patch only CH2 and CH4 outputs ...

    details
  • ALM Busy Tangle Quartet

    ¥26,900 (Tax excluded ¥ 24,455)
    In Stock
    4CH / 8HP high-quality linear VCA that can be mixed!

    The MUSICAL FEATURES Tangle Quartet is a clean and compact 4-channel linear VCA mixer. Only signals that are not patched to their individual outputs will be mixed from the mix outputs. Equipped with 4 clean VCAs with no sound leakage in a compact 8HP ...

    details
  • Erica Synths Black Quad VCA2

    ¥32,900 (Tax excluded ¥ 29,909)
    In Stock
    4CH VCA mixer with switchable response

    The MUSICAL FEATURES Black Quad VCA is a 4CH VCA module with the following features.4 independent VCA lin / log responses can be switched for each channel CV is internally wired to the next channel The output is mixed to the next output if unpatched ...

    details
  • Befaco HexMix VCA

    ¥40,900 (Tax excluded ¥ 37,182)
    In Stock
    6-channel VCA mixer with independent response control that doubles as an input VCA for the Hexmix system

    The MUSICAL FEATURES Befaco HexMix VCA is a compact 6-channel VCA mixer.Equipped with independent response curve control, CV input, and manual gain control for all channels, this unit is a 6-channel mixer by normalizing each channel output to channel 6 ...

    details


VCA with particular attention to distortion

The VCA that makes up the final stage of the synth voice has a large effect on sound quality, so if you want to add warmth to the sound, it is recommended to use a VCA that actively introduces distortion. There is also a VCA that uses a vacuum tube like L-1. Verbos Amp & Tone also has a filter, and you can combine the two to configure the latter part of the synth voice.
  • XAOC Devices Tallin

    ¥29,900 (Tax excluded ¥ 27,182)
    In Stock
    Compact VCA with compact sound quality and features

    The MUSICAL FEATURES Tallin is a 2-channel VCA with outstanding sound quality and functionality. Each channel has two CV inputs, EXP and LIN, in addition to the signal input (CV can also be input). EXP is suitable for tremolo control by envelope, LIN is LFO, etc ...

    details
  • Manhattan Analog DTA

    ¥14,400 (Tax excluded ¥ 13,091)
    Pre-Order
    Discrete VCA with vintage sound quality

    MUSICAL FEATURES Manhattan Analog VCA module composed of discrete circuits.Unlike the clean VCA, this one aims for a vintage sound and is aggressively colored by overdrive. It is based on the minimoog VCA circuit. D ...

    details
  • L-1 Tube VCA1 (1Ж24Б)

    Out of Stock
    Soviet '1Ж24Б' tube-based VCA with built-in feedback loop

    The MUSICAL FEATURES L-1 Tube VCA is a VCA / Distortion / Waveshaper / Timbral Gate designed based on the Soviet vacuum tube '60Ж70Б' made in the 1's and 24's. Inspired by Ken Stone's Tube VCA, this unit has an internal connection to input 2 ...

    details
  • Verbos Electronics Amp & Tone (2020 ver)

    ¥49,900 (Tax excluded ¥ 45,364)
    Pre-Order
    Discrete VCF + VCA compacted with transistor base

    MUSICAL FEATURES Amp & Tone is Verbos Electronics' new VCF + VCA module with discrete circuitry. The VCA is a transistor base and the filter is a Sallen-key type, making the size more compact.Increasing the input gain ...

    details


Low pass gate

The VCA and low-pass gate used in Buchla do not change the volume according to the voltage applied to the CV control, but always have a loose decay.Therefore, even if you use a gate etc. for CV instead of an envelope, it will sound naturally.Since the brightness of the sound also changes with the volume, you can produce a more vivid tone. The Erica Synth Black LPG has resonance and the Passive LPG 1U is passive and operational.
  • Make Noise Optomix (Rev2)

    Out of Stock
    Compact and versatile, the standard popular 2-channel low pass gate. It is Rev2.

    MUSICAL FEATURES Optomix is ​​a dual low pass gate module that can attenuate the input signal with a unique decay response. Optomix can also function as a built-in envelope VCA or envelope follower. As a sound quality, a very mild LPF is applied ...

    details
  • Make Noise LxD

    Out of Stock
    Dual low-pass gate that can also configure the VCF → VCA part

    MUSICAL FEATURES LxD (Low Strike Duo) is a low pass gate that has a different filter characteristic from Optomix. CH1 is a 12dB / Oct filter with a little resonance, CH2 is a 6dB / Oct filter with no resonance and is used with bactrol ...

    details
  • Erica Synths Black LPG

    ¥27,900 (Tax excluded ¥ 25,364)
    Pre-Order
    Erica's low-pass gate with Decay envelope generator and resonance drive

    The MUSICAL FEATURES Erica Synths Black LPG is a new low-pass gate module designed from the ground up by adding a unique resonance circuit to the combination of low-pass VCF and VCA. VCF cutoff frequency, VCA offset, operation mode (VCF / VCF + VCA / VCA) C ...

    details
  • Intellijel Designs Passive LPG 1U

    ¥6,900 (Tax excluded ¥ 6,273)
    Pre-Order
    Simple 1U passive lowpass gate based on bactrol

    MUSICAL FEATURES Passive LPG 1U is a simple passive low pass gate of Bactrol base, 1U. The acoustic characteristics of Bactrol LPG, which is a passive circuit that does not require a power supply, depends to some extent on the input audio signal, and can give a natural and organic change in the volume and timbre of the signal.

    details

Patch example using VCA

I've touched on a few things so far, but from now on, I'll show you how to use VCA in various ways through 11 patchings.

VCA Patch1. VC Attenuator

This is a patch that shows what it looks like as a Voltage Controlled Attenuator.The Quad VCA in the video has the Boost switch off and the response curve is linear, so the input signal is about 1x at the maximum knob position.The first half of this video shows the operation as an attenuator that is manually controlled, and in the second half, the voltage from Quadratt is patched to the CV input, and the amount of attenuation is controlled by the voltage.

 

VCA Patch2. Envelope-Controlled VCA

This is the most "normal" way to use VCA. By inputting the envelope voltage to the CV input of the VCA, the volume of the output signal increases from 0, reaches the peak, and disappears to 0.This is the basic mechanism of synthesizer pronunciation.Since the volume change is controlled by the input voltage, the time of the volume change is determined by the attack and decay time of the envelope.

 

VCA Patch3. Panning

Now, here is the advanced version.The first is a panning patch that uses two VCAs as stereo outputs (listen in a stereo environment).The output from the oscillator is connected to the signal inputs of the two VCAs, with Out 1 output to the left and Out 2 to the right.And if you connect a bipolar LFO to the CV input of the VCA on channel 1, you will only hear a sound when the LFO output is positive.Next, the signal that branched the output of the LFO is input to the atte inverter to create an LFO with the plus and minus inverted, and it is connected to the CV input of the VCA of channel 2 to pan left and right.

In the video, there is no sound when the LFO is 0V, but by raising the offset knobs of the two VCA, you can make the sound come out from both the left and right when the LFO = 0V.

 

VCA Patch4. VC Crossfader

A patch that mixes the outputs of two VCAs to crossfade the two sounds.The chord sound and the root single note are connected to separate VCA signal inputs, and the Quad VCA's mix function is used to output from Out 2 to mix the two notes.

If you connect a bipolar LFO to the CV input of the VCA on channel 1, the volume will be louder when the LFO output is positive and silent when the LFO output is negative.Next, branch the output of the LFO and input it to the atte inverter to create an LFO with the plus and minus reversed, and connect it to the CV input of the VCA of channel 2. When one volume is loudest, the other sound disappears. It will be.

 

VCA Patch5. Ducking

A ducking / side chain patch that reduces the volume of the chord sound that keeps ringing at the timing of the kick.

The gate signal is split into two with multiples, one connected to the kick trigger input and the other connected to the envelope trigger input.Connect the chord sound output from another oscillator to the VCA's channel 2 signal input.

Input the output of the envelope triggered with the kick to the atte inverterNegative envelopeAnd connect it to the CV input of the VCA on channel 2 where the code is being input.This creates a sidechain that triggers a kick according to the envelope setting and at the same time reduces the volume of the chord sound.

 

 VCA Patch6. VC Delay Feedback

This patch controls CV control of delay feedback via VCA.

Input the arpeggio sound to channel 2 of the VCA with the level knob maximized, then connect it to the delay audio input set to 100% dry and output that sound.

The Quad VCA Out 2 is input to the delay to mix with the sent delay sound.Then connect the output of the T1 out of the delay module, which is the output of one delay, to the channel 2 signal input of the VCA.As a result, the delayed delay sound is mixed with the arpeggio sound and input to the delay, creating a feedback path for the delay.

By connecting an LFO to the CV input of channel 1 of the VCA, it is possible to control the feedback with the CV.

 

VCA Patch 7. Half Wave Rectifier

It is a rectifier patch that takes out only the positive side of the voltage that fluctuates with plus or minus.

VCA's CV in uses the property that voltages below 0 are invalid and operate as 0V. If you connect an offset voltage of 5V to the signal input of the VCA with the level knob turned down, and connect a bipolar LFO that operates in the range of minus to plus to the CV input of the VCA, the Half Wave Rectifier outputs the CV only when the LFO is plus. It will be.

In the video, I patch the FM input of the oscillator to the LFO output and check it.

VCA Patch 8. LFO Amount Modulation

 A patch that modulates the depth of LFO modulation with another LFO.

In the patch below, the oscillator sound is passed through the uVCF of the filter.Connect the descending sawtooth LFO to the VCA signal input and connect its output to the FM1 input that controls the uVCF cutoff.

Next, connect a slower triangular LFO to the CV input of the same VCA and turn the attenuator knob to the right to change the level of the LFO and change the depth of the cutoff modulation.

 

VCA Patch 9. Gating triggers

It is a patch that creates a rhythm by controlling the ON / OFF of the stream of the trigger signal such as a clock with an LFO.

Connect the trigger signal that ticks the rhythm at regular intervals to the signal input of the VCA, and connect the output to the trigger input of the hi-hat. If you turn the VCA Level knob all the way to the right, the hi-hat will sound when the trigger signal level rises from 0.

If you connect the output of the LFO to the CV input of the VCA where the trigger is input, the level of the trigger signal will change depending on how the LFO swings, and the hi-hat will not sound when the LFO level is low.The rhythm of the hi-hat can be kept constant.

If the trigger signal sounds while it is high, the timing of the beginning of the hi-hat sound may be off the head of the trigger, so make the trigger as short as possible.
Like the end of the video, you can also use the LFO you are using for CV input to change the tone.

VCA Patch 10. Amplitude Modulation (AM)

Amplitude Modulation patch that modulates the volume of the oscillator (carrier) input to the VCA with a different oscillator (modulator).

Buchla & Tiptop Audio Dual Oscillator Model 258t The upper oscillator is used as a carrier and its output is connected to the signal input of VCA. Connect the lower oscillator of 258t as a modulator to the CV input of the VCA.
Setting the modulation pitch to the audible range has the effect of producing a sound with many overtones, and lowering the pitch to the LFO range below the audible range produces a tremolo-like effect.

If you want to add a scale to a tone created by AM in the audible range, you can add a scale while maintaining the atmosphere of the tone created by AM by inputting the same CV not only to the carrier but also to the modulator. ..

VCA Patch 11. Creating Velocity

This is a velocity patch that adds strength to the volume envelope of the hi-hat with an LFO.

For the hi-hat sound, the Noise out of Verbos Electronics Noise & Filter is connected to the signal in of VCA, and the envelope of ALM Busy Pip Slope mk II is input to the CV in.

The rhythm pattern in the video is ALM Busy Pamela's New Workout Outputs 1 triggering the bass drum module Tiptop Audio BD909 and Outputs 4 set to 2x speed triggering the hi-hat.The hi-hat trigger is connected via multiples for patching, which will be described later.

Before patching to the CV-in of the VCA that is passing through the noise, pass the envelope once through the signal-in of another VCA (VCA for velocity).This not only allows you to adjust the output level of the envelope with the VCA's LEVEL knob, but also allows you to adjust the strength with the CV.
This time, the 3 / 1 speed triangular wave LFO output from Outputs 1.5 of Pamela's New Workout isVCA for velocityBy connecting to the CV input of and turning the attenuator knob to the right, the hi-hat sound carved in 16th notes was added or weakened.

In the case of the above patching, the level of the envelope will change during the sounding of the hi-hat because the waveform of the LFO will change between the time the hi-hat is triggered once and the next time it is triggered.If you want to brush up the patch further, trigger a forked hi-hat.Sample & holdIf you use the voltage sampled from the LFO with the hi-hat trigger using (SSF / Divkid RND STEP), you can create a CV that holds the LFO signal while sounding, and the patch will be closer to the original velocity. increase.When I actually reconnected the cable to which the LFO was connected to the output of the RND STEP, the level of the hi-hat envelope changed for each pronunciation, and the strength became clearer.

Finally, I input the sample & hold CV with strength and weakness to the Decay CV in of Pip Slope mk II so that when the hi-hat sound is loud, it becomes longer like an open hi-hat.

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