Learn the Modules
Getting the most out of modular synthesis takes a lot of time, patience and experimentation. It's important fully understand how each module in your system works to get the most out of them. You might be surprised how flexible seemingly ordinary modules can be.
The Pocket Operator Modular series has 12 modules in the collection:
M-1 / M-2 / M-3 | Square, Saw and Sine (400 / 170)
Oscillators are modules that generate a tone using a rapidly oscillating signal. They are normally used as the foundation of a synth voice. The POM-400 as 3 oscillator modules – Square, Saw and Sine. POM-170 only has the Square module.
The oscillator's pitch can be tuned manually using the 'tune' knob or from a CV controller, such as the POM-16, through the 'key' input. The two additional control inputs labelled 'control' and 'fm' allow you to modulate the frequency of the oscillator, meaning you can dial in mild vibrato or crank it up to some sci-fi laser sounds. On the Square oscillator, the 'fm' is replaced by a 'pwm' input (pulse-width modulation). This controls the shape of the waveform.
M-4 | Filter (400 / 170)
A filter removes or reduces frequency content from an audio signal. There are a variety of filter types out there, but the M-4 is a 24db/oct low-pass. This means it allows low frequencies to pass through it, while reducing frequencies above cutoff point set by the 'frequency' knob. The 'resonance' control adds a bump at cutoff point, giving you the characteristic sweep sound when 'frequency' is adjusted (check out the patches below to see what we mean).
There are two 'control' inputs on the filter, both linked to the 'frequency' control. This allows you to sweep or shape the filter using other modules or CV signals.
M-5 | Envelope (400 / 170)
The envelope module ('env' on the panel) is used as a shaping tool for your patch. You'll find 2 of these on POM-400, and 1 on the POM-170. When triggered by an input signal such as gate or trig, the CV output rises and falls through the 4 stages of the envelope:
Attack - Determines the time it takes for the voltage to rise to peak level.
Decay - The time it takes for voltage to fall to the sustain level (unless sustain is 100%)
Sustain - Once attack and decay sections are complete, sustain is level at which the voltage is held, providing a signal is continuously present at the input.
Release - Once the input signal is gone, release determines the time it takes for the voltage to return to 0.
This module is commonly used with a VCA or Filter to create the familiar sound shapes. It can also be easily connected to other modules for some more experimental patch ideas.
M-6 | VCA (400 / 170)
The 'VCA' or Voltage Controlled Amplifier controls the amplitude of the signal passing through it. Imagine it a bit like a volume fader on a mixing desk (we have a more in depth blog post on this subject here). You will find 2 on the POM-400, and 1 on the POM-170. You can control the amplitude of a signal manually using the level control, but the VCA is most useful when combined with a gate or envelope connected to the 'control' input. For instance, if you connect a gate out from the POM-16 keyboard, the VCA will only let sound through when signal is present. For more control over the shape of the amplitude, you can use the 'env' module instead. For more advanced users, VCAs can also be a useful tool to shape & attenuate CV signals, which we'll explore later in our 'Patch Ideas' section.
M-7 | Mixer (400)
On the POM-400, there are a lot of potential signals to route through a patch. It's always handy to have a mixer to keep them all in check. The mixer module has 3 inputs with level control and 1 output with master level control. This is immediately useful to balance signal from the 3 oscillators. Unlike the VCA, the mixer only has manual controls, so it's not designed for shaping sound. However, it can also be a useful tool to mix multiple CV signals for complex modulation.
M-8 | Noise (400)
This module simply outputs 2 continuous noise sources - white noise and saw noise. White noise is completely random, where as saw has a particular character that makes it slightly less random, but just as noisy! Both are useful as random modulation sources, or as a foundation for percussion patches. They also work really well with the 'rand' module.
M-9 | Rand (400)
Rand is a sample & hold module on the POM-400. It samples voltage level from the input and holds it for a length of time set by the rate control. As an example, if you patched in a saw shaped waveform, the slope section would turn into steps (like a staircase) as the sampled level is held at each point. The slower the rate, the bigger the steps. This module can be combined with the noise or the LFO can create some interesting modulation outputs.
M-10 | LFO (400 / 170)
The LFO or low frequency oscillator is a free running modulation source with simultaneous square and triangle outputs. An LFO is very much like a normal oscillator, except that it oscillates ranges below human hearing. So while this doesn't make it great to listen to, it does it make it a useful tool for slowly modulating different modules. Typically you'd find this connected to the filter control, or fm input on the oscillators. However it can be used for some slightly more unusual purposes such as a clock source.
M-11 | Speaker (400 / 170)
To add to the idea of a portable modular synth, both the POM-400 and POM-170 come with a built-in speaker. The whole output section also features a line out to plug your synth into a mixer or interface, making it easy to plug in, play and record your patches.
M-12 | Sequencer (400)
The sequencer module is a 16-step sequencer with a few tricks up it's sleeve. Each step has a variable voltage output controlled by the knobs labelled 1-16. By default it runs through all steps, but when you turn the knob on a step fully clockwise, it jumps back to the beginning. You can also restart the sequence by triggering the 'reset' input, change direction using the <- -> input, and skip to steps 1, 5, 9 & 13 using the D1, D2, D3 & D4 inputs. These additional controls allow you to expand the 16 steps with greater variation.
And that concludes the list of modules in the Pocket Operator Modular System! It may seem like a lot to process, but their applications will become more familiar when you use them. You will also find if you really take the time to understand each one, they will still surprise you with what they can add to a patch.