Frequency Central

Notes: Arcade performance buttons for gating and actuating.

You can use Asteroids in two different ways:

Gate generator using the two outputs. A 5V gate will be output when the relevant button in pressed.

Momentary manual actuator. Whatever is present at the relevant input will be output when the button is pressed.

Product Specifications

12V draw: 7mA
-12V draw: 0mA
5V draw: 0mA
Depth: 25mm
Width: 8HP

Notes: A couple of years back, Frequency Central developed Cosmic Background as a standalone percussion voice. The concept was to bundle all required sub-modules behind one panel, pre-patched, yet also fully modular, with each sub-module having its own inputs and outputs. This proved to be a very popular product, but Frequency Central decided to replace Cosmic Background's noise generator with a VCO (and do a few other tweaks), creating a cute little fully modular synth voice ripe for sequencing - and that's how Dark Star was born!

Dark Star consists of 4 sections:

Voltage Controlled Oscillator based on AS3340 with sawtooth, triangle and pulse waveforms
Voltage Controlled Filter with lowpass and highpass options, Drive control, Sweep control which attenuates amount of Release CV
Release generator with CV input for voltage control of release time. Option for sustain via jumper on rear panel.
Voltage Controlled Amplifier
Together they form a pre-patched super versatile analogue synthesiser voice.

Additionally, each section is fully modular in it's own right, so there are patch points for:

1V/oct CV input
PWM CV input - attenuator doubles as manual pulse width when no external signal is present
Gate input for Release or Sustain/Release
Release CV input for voltage control of Release time
VCF audio input with attenuator, for introducing external audio
VCF CV input with attenuator (1V/oct CV is normalised to this input)
VCA audio input (VCF is normalised to this input)
VCA CV input (Release CV is normalised to this input)
Release CV output
VCO audio output
VCF audio output
VCA audio output

Here are some useful patches to try:

Release CV output to PWM CV input, for swept PWM
VCF OUT to VCF IN, thickens and further overdrives the filtering
VCO OUT to VCF CV input, for fizzy FM of the filter
Use a multiple to patch 1V/oct to Release CV input, lower notes will have longer release, higher notes will have shorter release

Product Specifications

12V draw: 28mA
5V draw: 0mA
-12V draw: 28mA

Depth: 35mm
Width: 16HP

Notes: Pretzel Logic is a 4 bit to 16 step addressable analogue sequencer which outputs gates. Each of it's 16 steps can be addressed in any order for ultimate creative flexibility. It pairs nicely with Polygraf, High Towers and Akropoli; together they make a powerful combination.

It features 4 address inputs, 1, 2, 4 and 8, each of which has an associated input socket as well as a 3 position state switch which allows each address input to be held high, respond to input signals, or held low. Each input has two status LEDs. The red LED displays the signal present at the input socket, while the green LED displays the status of the address input. The combination of signals present at the input sockets, together with the positions of the state switches allows Pretzel Logic to have 16 different output states, numbered from 0 through to 15. The output state of Pretzel Logic can be ascertained by observing which of the 4 address inputs are high. So, for example:

- If no green status LEDs are on, Pretzel Logic is in output state 0

- If green status LED 4 is on, Pretzel Logic is in output state 4

- If green status LEDs 1, 2 and 4 are on, Pretzel Logic is in output state 7

- If green status LEDs 2 and 8 are on, Pretzel Logic is in output state 10

The input sockets may be addressed by various external modules, for example:

- FC Pocket Calculator, FC High Towers, or similar clock dividers with multiple outputs from other manufacturers.

- FC Polygraf or similar grid editors from other manufacturers.

- FC Little Melody, Akropoli or similar.

As Polygraf is capable of storing many user patterns which themselves are selectable by CV, multiple chained patterns are possible. Furthermore, we accept that users will discover their own unique combinations of FC and third party modules to address Pretzel Logic, always bearing in mind that at any time the status of any of the 4 input sockets may be overridden by the 4 state switches. Pretzel Logic may be latched manually via the Latch toggle switch, or externally via the Latch input. When Pretzel Logic is latched, the last output state to go high is held until Pretzel Logic is unlatched.

Notes: Shapes is a wide ranging and fully analogue oscillator which can perform duties as both auxilliary VCO* as well as VC-LFO. Shapes can be configured to cycle continuously, or to provide one-shot shaped outputs. When set to one-shot mode, Shapes may be used as an ersatz envelope generator.

Using the Time knob, Shapes can cycle from as low as 8 seconds (whale song) to as high as 19500Hz (bat beeps).

Shapes has 3 simultaneous outputs:

sawtooth (+/-5V, 10Vpp)
ramp (+/-5V, 10Vpp)
triangle (+/-5V, 10Vpp)
Additional waveforms may be derived courtesy of the Shape knob. Anticlockwise from 0 achieves progressively logarithmic sawtooths and ramps, whereas clockwise from 0 achieves progressively exponential sawtooths and ramps. The effect of the Shape knob on the triangle waveform is asymmetric, anticlockwise from 0 achieves progressively logarithmic leading edge, whereas clockwise from 0 achieves progressively exponential falling edge. Progressively exponential triangle waveforms can be achieved using the Time CV knob (set Shape knob to 0) providing there is no jack in the Time CV input socket

Time CV input provides wide ranging control of time. It is possible to dial in something approaching 1V/oct over a limited range, although Shapes has not been designed to perform as an accurately tracking VCO. In the audio range, Shapes comes into its own when used as a 'daughter' VCO to an external 'mother' VCO by patching the 'mother' VCO into Shapes' Gate In input socket - some impressive oscillator sync style effects can be achieved.

Gate In can also be used to initiate waveforms in one-shot mode, where a pulse of any length will cause Shapes to complete one cycle.

*Shapes has not been designed to perform as an accurately tracking audio VCO.

Product Specifications

12V draw: 15mA
5V draw: 0mA
-12V draw: 15mA
Depth: 45mm
Width: 4HP

Notes: Chris Huggett, chief designer at EDP came up with a novel little circuit for the filter envelope of the Wasp, based around half a CD4013, half a CD4066 and half a LM3900. It was an A/R generator with looping option which would proceed through its whole cycle from only a trigger input. He further developed the circuit for the filter envelope in the Gnat to use just one knob to provide a range of attack envelopes when anti-clockwise (from 12 o'clock), and a range of release envelopes when clockwise (from 12 o'clock). 12 o'clock gives a very short symmetrical blip. As you can build two of these with a CD4013, CD4066 and LM3900, Frequency Central have provided both a two knob version and a one knob version, each has its own place.

Both envelope outputs are 0V to 5V.
All Q and not-Q outputs are 0V to 8V
Upper section cycle times: 23Hz to 20 seconds
Lower section cycle times: 8Hz to 10 seconds

Product Specifications:

Depth: 39mm
Width: 8HP
12V draw: 30mA
-12V draw: 0mA
5V draw: 0mA

Notes: Wonderland is an 8×8 active patchbay/matrix mixer/switcher for both audio and control voltages. It features:

8 inputs (1 through to 8), each with micro-attenuators (which can be set with a small screwdriver)
8 buffered inverted outputs (A through to H) which are 180o out of phase with the inputs
8 buffered normal outputs (A through to H) which are in phase with the inputs
A switch matrix of 64 push on/push off switches
Any of the 8 inputs can be patched to any of the 8 outputs simply by pressing the corresponding switches. A patched signal will appear at both normal and inverted outputs simultaneously.

A single input can be patched to a single output. A single input can be patched to multiple outputs. Multiple inputs can be patched to a single output. Multiple inputs can be patched to multiple outputs.

Each input features a micro-attenuator which can be set with a small screwdriver. This space saving feature allows you to reduce the volume of an incoming signal without having to resort to external attenuators. If you add many inputs to one output you will of course cause clipping (which may or may not be desirable!), the micro-attenuators are your on-board way around this. I find it useful to leave the micro-attenuators set to 50% (which is how they come pre-set at delivery). Of course, their size is a little bit of a compromise, but they are a useful feature nonetheless. Wonderland’s sister module Looking Glass includes full size input attenuators as well as LED status indicators.

Product Specifications
12V draw
30mA

5V draw
0mA

-12V draw
31mA

Depth
35mm

Width
18HP