In the context of electronic audio equipment, a stage is a functional block of circuitry that performs a specific task. For example, a 'four-stage' phaser effects pedal employs four all-pass filter circuits. An individual stage could be a preamplifier, an insert return buffer, a section of an equaliser, or a mix-bus amplifier, for example, and the process of optimising the signal level passing through each stage is called gain-staging. 

Also known as a Phase-Rotator. An electronic filter circuit that doesn't change the amplitude of any signal passing through it, but which alters the phase of the signal at different frequencies in a non-linear way. Used as a core element of phaser effects pedals, and also in broadcast processors to help make asymmetrical audio signals symmetrical (which allows a slightly higher output level before clipping). 

See All-Pass Filter

Least Significant Bit. In a binary number the bit that carries the smallest multiplier value (units) is deemed the least significant bit, and is typically the right-most digit in a binary number. The three-bit binary equivalent of the decimal number 1 is 001, and the bit showing 1 is the LSB.

Most Significant Bit. In a binary number the bit that carries the largest multiplier value is deemed the most significant bit, and is typically the left-most digit in a binary number. So the three-bit binary equivalent of the decimal number 4 is 100, and the bit showing 1 is the MSB.

A plosive is the strong puff of air from the mouth which is generated when speaking or singing syllables with 'b's or 'p's. if a plosive blast reaches a microphone's diaphragm it can create a large unwanted low-frequency signal and distortion (see Wind-shield).

See Wind-Shield

A mechanical acoustically-transparent screen placed in front of or completely enveloping a microphone to prevent moving air currents from impacting the diaphragm and generating unwanted noise. In studio use a wind-screen is typically used to prevent plosive blasts from vocals or speech reaching the mic diaphragm, and it's typically a large disc made of a two layers of mesh fabric, a perforated metal disc, or an open-cell foam disc. In location sound gathering applications a wind-shield is typically a large fabric-covered frame which completely envelopes the microphone with a volume of still 'dead air'. 

Saturation is a mild form of dynamic and harmonic distortion typically associated with bringing 'warmth' and 'body' to a sound. The term relates to a process which can occur in transformers when the magnetic flux generated by the input signal fully magnetises the transformer core such that it cannot then accurately pass any larger audio signals, resulting in audio compression and harmonic distortion. A similar effect can occur with magnetic tape heads and tape itself. These saturation effects can now be emulated electronically and digitally, often with user controls to fine tune the effect characteristics.