LFO

Low Frequency Oscillator

It is an oscillator circuit that employs simple waveforms and does not generate audible frequencies(sub-audio band). It is used to modulate the trend of other synthesis parameters. It consists of several parameters, the most common of which are:

• RATE: frequency of oscillation
• RESET: input to reset the wave cycle
• SYNC: input to synchronize the oscillator
• RANGEL/M/H: you can set the range of the oscillation speed(low, medium, high).

In the eurorack world many oscillators also act as LFOs, usually selectable with a switch (e.g., Intellijel Rubicon).

Some examples of LFOs :

Doepfer A-147 VCLFO

The Doepfer A-147 is a low-frequency oscillator that repeatedly generates simple wave cycles with an oscillation range of 0.01Hz to 50Hz. Compared with the A-145 and A-146 modules, it can be voltage controlled, and also has a RESET input for sync with other LFOs. It has 4 waveform outputs : triangular, sine, square and sawtooth.

Make Noise Function

The Function is a part of the Maths module, a triangular, exponential or linear waveform generator that can be used for various functions. Through the RISE and FALL controls, it is possible to manage the rising and falling edge of the waveform; the speed of oscillation will also depend on this. So it can be used as a VCO, LFO or envelope generator with Attack and Release. There are two outputs on the panel, one positive and one inverted. It also sends gate signals at the end of the rising edge reading and at the end of the wave cycle. The first oscillator has a switch to enter phase lock and hard sync with the second. The second VCO has the FINAL wave. On the right side of the panel you can decide its harmonic content and wave type.

Mutable Instruments Frames

The Frames is one of the most versatile modules in the eurorack world, in fact besides being a 4-channel VCA it can be used as a programmable CV generator, step sequencer and LFO. It has 4 inputs, 4 outputs and a mix output. Inspired by the concept of keyframing it can save up to 64 configurations for the 4 controls. Each frame can be selected via the FRAME KNOB which in turn can be voltage controlled.