Weak current College】 【amplifier for main performance indicators.

Amplifier main performance indicators have output power, frequency response, distortion, Snr, output impedance, damping coefficients, etc.

Output power: units of W, because the manufacturers of measuring methods, so there are some names different name. For example the rated output power, Max output power, output power music, peak output power of music.

Music power: mean output distortion does not exceed the specified value, the power amplifier on the music signal instant maximum output power.

Peak power: refers to the condition without distortion, amplifier's volume to the maximum, the amplifier's output for maximum music power.

Rated output power: when harmonic distortion for 10% of the average output power. Also called maximum useful power.

Generally, peak power is greater than the power of music, the music more than rated power, generally speaking peak power is the rated power of 5-8 times.

Frequency response: indicates that the power amplifier frequency range, and frequency range not uniformity. Frequency response curve of flat or not usually expressed in decibels [db]. Home HI-FI amplifier frequency response usually 20HZ--20KHZ and negative 1db. this range is wide, the better. Some of the best amplifier frequency response already done 0--100KHZ.

Distortion: the ideal amplifier should be put after the input signal amplification, no change of faithfully restored. However, for various reasons the power amplifier is enlarged by signal is compared with the input signal, often have a different degree of distortion, this distortion is distorted. Use a percentage, its value as small as possible. HI-FI amplifier distortion at 0 of the total. 03%-0. 05%. Amplifier distortion with harmonic distortion, intermodulation distortion, crossover distortion, clipping distortion, transient distortion, transient intermodulation distortion, etc.

SNR: refers to the power amplifier output of various noise level and the ratio of the signal level, db, the higher the value, the better. General Home HI-FI amplifier of signal to noise ratio in more than 60db.

Output impedance: pair of speakers the equivalent resistance, called output impedance.