This is a linear Mixing Desk control capable of providing adjustment of audio signal level.

Feedback is the screeching or howling sound caused by feeding the output of an audio system back to its own input, for example pointing a microphone at the speakers that are the output of the microphone signal. This causes amplification of the already amplified signal in an endless loop resulting in an overload of the audio circuitry.

There are several different kinds of filter:


This is a low-pass filtered used in digital audio equipment.

Band Pass

Passes a band of frequencies between two limits.

High Pass

Passes frequencies above a threshold frequency.

Low Pass

Passes frequencies below a threshold frequency.


Passes frequencies above and below a chosen band of frequencies. i.e. it cuts frequencies within the chosen bandwidth.

See our Filters reference article by following the link below.
Songstuff Filters Article

Used to create a ‘flanging’ effect. Flanging is commonly done using an electronic processing device to filter an input signal. This treatment introduces harmonically related notches in the filter response.

This is an audio feed sent to the performer using speakers or headphones to allow them to monitor the sounds they are producing.

Freewheel Sync
A.K.A. Flywheel Sync. Using tape sync there were frequent timecode dropouts. Freewheel synchronization will interpret corrupted values.

This is the ratio of the wavelength of a waveform to time. In particular it is the measure of how many times a wave form will repeat in 1 second.

Frequency = Wavelength * Time

Frequency Modulation (FM)
Frequency Modulation is the alteration of the frequency of one oscillator, controlled by the amplitude of a modulating signal.

Basically the amplitude of the modulating signal dictates the amount of deviation from the carrier frequency, and the frequency of the modulating signal dictates the rate at which the deviation occurs.

Frequency Response
This is the variation of the gain of a device or system with audio frequency.

Metallic strip typically made of nickel-silver. Mounted on the fret board, a fret marks the position on the guitar neck where a guitar string will create a specific pitch, when pressure is applied behind the fret to shorten the guitar string length.

Fret Board
Face of the guitar neck, directly under the strings. The guitar frets are mounted on this board.

FSK Sync
An old form of clock sync. Commonly used with the early Atari sequencers and drum machines.