What's it mean?


Cab: an informal term given to cabinets, these contain one or more speakers.

Castors: the small wheels on the base of a unit that allow it to be moved more easily.

Combo: a combo consists of an amplifier and one or more speakers contained in a cabinet.

Earth/Earthing/Earthed: may also be referred to as grounding. Proper earthing leads to a reduction in unwanted noise and ensures product safety.

Frequency (and frequency response): the number of waves produced by a source each second. The frequency response is a measurement of the output compared to the input.

Fret: the material that covers the front of a unit, it may vary in colour or design.

Hertz and kilohertz: the unit that frequency is measured in. Kilohertz is 1,000hertz.

Instrument level: these signals vary as they occur between mic and line level signals.

Line level: the signals that are highest before amplification.

Mic level: these signals are the weakest level and can only be brought up to line level after the preamplifier stage.

PCB: printed circuit boards that are manufactured in an automated process.

Point-to-Point: a method of producing circuit boards that involves hand-wiring techniques.

Speaker level: these signals occur after amplification and rely on speaker cables for safe signal transfer.

Voltage: this is the pressure from a power source that pushes the current through a circuit. Measured in volts (v).

Wattage: this is the operating power of your unit. Measured in watts (w).


Auto wah: this creates a wah effect without the manual manipulation of the pedal. Playing lightly will give a soft wah whereas playing with force will give a more aggressive wah effect.

Bias: an electrical current that must be at the optimum setting to ensure that your power valves run efficiently.

Chorus: an effect that creates a richer sound, mimicking multiple performers playing the same part.

Clean tone: the original tone produced by a guitar and amp without any distortion or other FX.

Compressor: this effect decreases any guitar sound that peaks above a certain threshold to add clarity.

Crunch: a tone with a slight amount of distortion. Crunch can also be described as a mild overdrive.

Delay: an echo effect that is produced as the FX unit records an input signal and plays it back.

Distortion: an effect that often results in a gritty or fuzzy tone.

DI-Output: used to connect your amplifier to an external recording device.

Equalisation (EQ): the process of altering the frequency response of an audio system, usually by reducing bass or treble frequencies. The frequency response affects how closely an amp reproduces the input sound from the guitar.

  • Bass: these tones have a frequency at the low end of the human hearing range. 

  • Middle: these tones have a frequency in the middle of the human hearing range.

  • Treble: these tones have a frequency at the higher end of the human hearing range.

  • Presence: an equalisation setting that will increase the higher frequencies of your sound.

  • Resonance: an equalisation setting that will increase the lower frequencies of your sound.

Flanger: this effect creates a chorus-like sound but is more vivid and harmonically complex. It can produce ‘jet plane’ or ‘whooshing’ sounds.

Footswitch: a device that allows a guitarist to change the settings of the amp from the floor without needing to touch the controls.

Frequency Dependent Damping (FDD): this special technology emulates the sound and behaviour of a valve amp. It gives a tighter and more defined sound.

FX: the name given to sound effects used in music.

FX loop: this loop involves the signal travelling from an amp, to the effects processer and then back to the amp. You’ll notice a send and return jack on your amp.

Gain: the input volume to the preamp stage that can be controlled. Changing this will change the overall volume. It also sets the level of distortion in your tone. 

Head: the term used to describe an amplifier on its own without a speaker.

Impedance: the load connecting to the speaker socket on the amplifier or combo to give the maximum power transference. Measured in Ohms.

Master volume: the output volume.

MIDI: this stands for Musical Instrument Digital Interface. A MIDI instrument can exchange information with a computer and this allows for easier recording or composing.

Output level: this is an adjustable feature that determines the amount of output available depending on the level of power selected. At a high power, the output is at maximum.

Overdrive: a type of distortion achieved by increasing the gain on a valve.

Powerstem™: works by reducing the voltage rails around the power amplifier. The voltage to the power amplifier is separated from the voltage to the rest of the amplifier meaning that it can be adjusted independently. By reducing the voltage available, the output power is limited by Powerstem™ and adjusts the voltages at the power amplifier section.

This offers power reduction on higher-powered models without changing the sonic character and so provides optimum tone and performance regardless of the volume level required by guitarists.

Phaser: gives a ‘shimmering’ effect to your sound. Some people also describe this as an ‘other worldly’ effect.

Reverb: mimics the sound that would be created if an instrument was used in a large echo-y space.

Re-bias: the process of matching the bias to the valves that have been used.

Stomp box: this is another word for pedal, a device placed on the floor that is connected to the guitar and amplifier. 

Sustain: an effect that increases the length of time a sound exists before becoming silent.

Tilt control: this adjusts the voice of your amplifier from normal to high treble at input stage.

Tremolo: this effect causes a rhythmic change to the volume of a signal.

Valve: in some countries this may be referred to as a tube. Valves are responsible for increasing the amplitude or power of a signal.

  • Power amp: feeds the larger signal from the preamp to drive the speaker through the output transformer. This is achieved using power valves.

  • Pre amp: the pre amp stage within the amplifier takes the weak signal from your amplifier and strengthens it to an output signal that can be processed by the power valves.

ValvestateTM: a technique that places a valve into the preamp section of the amplifier while the rest of the amp retains its solid-state technology. Amps that use this technology are essentially hybrids of valve and solid state amps.

Vibe: gives a hypnotic, pulsating effect to a sound.

Vibrato: this effect causes a rhythmic change in pitch.

Wah: best described as a crying tone that mimics the human voice.


Cab: an informal term given to cabinets, these contain one or more speakers.

Castors: the small wheels on the base of your unit that allow it to be moved more easily.

Impedance: the load connecting to the speaker socket on the amplifier or combo to give the maximum power transference. Measured in Ohms.

Mono vs stereo: mono units can power a single speaker while stereo units can power more than one speaker.

Speaker: the device found within your cabinet that converts electrical input into audible sound.

Speaker sensitivity: a measurement of the speaker’s output that gives an indication of speaker efficiency. Measured in decibels (dB).