Fever Glossary

HI-FI is derived from English, meaning "high fidelity".

Fire cow Abbreviation: cow, refers to power transformer, ring cow refers to ring core transformer. Square cow refers to E-shaped core transformer.

CD record A digital music disc jointly developed by Sony and Philips, with two specifications of 12cm diameter and 8cm diameter. The former is the most common, which can provide 74 minutes of high-quality music.

DVD A new generation of ultra-large capacity optical disc with a CD-like appearance, which will be widely used in high-quality audio and video program recording and as a mass storage device for computers.

HDCD High Definition Compact Disc (HDCD) Abbreviation - an encoding system that improves the sound quality of CDs, compatible with traditional CDs, but needs to be played on a CD player with HDCD decoding or connected to an external HDCD decoder to achieve the improved effect.

D/A converter A device that converts digital audio signals into analog audio signals in digital audio products (such as CDs and DVDs). D/A converters can be made into independent machines to be used with CD turntables, and are often called decoders at this time.

Preamplifier (pre-stage) The pre-amplification and control part before the power amplifier is used to enhance the voltage amplitude of the signal, provide input signal selection, tone adjustment and volume control functions. Preamplifier is also called pre-stage.

Power amplifier (post-stage) It is referred to as power amplifier. It is an electronic device used to enhance the signal power to drive the speaker to make sound. A power amplifier without auxiliary functions such as signal source selection and volume control is called post-stage.

Integrated amplifier An amplifier that combines the preamplification and power amplification parts in one chassis.

Single-ended amplifier The output stage of the power amplifier is completed by an amplifier element (or multiple elements but connected in parallel into a group) to amplify the positive and negative half-cycles of the signal. Single-ended amplifiers can only adopt Class A working state.

Push-pull amplifier The output stage of the power amplifier has two "arms" (two groups of amplifier elements). When the current of one "arm" increases, the current of the other "arm" decreases, and the states of the two are switched in turn. For the load, it seems that one "arm" is pushing and the other "arm" is pulling, and they jointly complete the current output task. Although Class A amplifiers can be push-pull amplifiers, it is more common to use push-pull amplifiers to form Class B or Class AB amplifiers.

Class A (Class A) A class of amplifiers in which no power output element of the amplifier will be current cutoff (i.e. stop outputting) during the entire cycle of the signal (the positive and negative half cycles of the sine wave). Class A amplifiers generate high heat when operating and have very low efficiency, but their inherent advantage is that there is no crossover distortion. Single-ended amplifiers all operate in Class A mode, and push-pull amplifiers can be Class A, Class B, or Class AB.

Class B (Class B) A class of amplifiers in which the positive and negative half cycles of the sine signal are amplified and output by the two "arms" of the push-pull output stage in turn, and the conduction time of each "arm" is half of the signal cycle. The advantage of Class B amplifiers is high efficiency, but the disadvantage is that crossover distortion will occur.

Class AB (Class AB) Between Class A and Class B, the conduction time of each "arm" of the push-pull amplifier is greater than half of the signal cycle but less than one cycle. Class AB amplifier effectively solves the crossover distortion problem of Class B amplifier, and its efficiency is higher than that of Class A amplifier, so it has been widely used.

AV amplifier An amplifier specially designed for home theater use, generally with more than 4 channels and surround sound decoding function.

HI-FI amplifier A high-fidelity amplifier, usually with two channels, with high technical indicators.

Tube amplifier Another name for tube amplifier.

Stone amplifier Another name for transistor or integrated circuit amplifier.



Bi-wiring A wiring method that uses one set of amplifiers and two sets of speaker cables to transmit the high and low parts of the music signal respectively. Bi-wiring requires the use of specially designed speakers with two pairs of wiring terminals.

Bi-amping A connection method in which each speaker unit of the speaker is driven by an independent amplifier channel. A pair of two-way speakers requires two stereo amplifiers and two pairs of speaker cables.

Dynamic range The level difference between the strongest part and the weakest part of the signal. For equipment, dynamic range refers to the equipment's ability to handle both strong and weak signals.

Frequency response (abbreviated as frequency response) Measures the ability of an equipment to reproduce high, medium and low frequency signals evenly. There are two requirements for equipment frequency response. One is that the range should be as wide as possible, that is, the lower limit of the frequency that can be reproduced should be as low as possible and the upper limit should be as high as possible; the other is that the response of each point in the frequency range should be as flat as possible to avoid excessive fluctuations.

Transient response The equipment's ability to follow sudden signals in music. Equipment with good transient response should respond immediately when a signal comes, and stop abruptly when the signal stops, without any delay.

Signal-to-noise ratio (S/N) is also called signal-to-noise ratio. The comparison between the useful components of the signal and the noise, often expressed in decibels. The higher the signal-to-noise ratio of a device, the less noise it produces.