For the matching problem between the power amplifier and the hifi sound system for home, in addition to the soft matching of the sound (the sound is often said to be soft and hard, it is based on the designer's design and materials for the tone color, but has the characteristics and personality) and some hard features on the technical indicators. Soft collocation is based on experience accumulation and personal hobbies. The hard collocation is based on data and basic technical common sense. The following is a brief description of the problem of hard collocation.

Impedance matching

1. When the vacuum tube amplifier (amplifier) is matched with the speaker, the output impedance of the amplifier should be equal to the impedance of the speaker, otherwise the output power and distortion will be reduced. Fortunately, most of the amplifiers have variable output impedance matching interfaces such as 4-8-16 ohms, and the impedance matching with the speakers has become simpler.

2. Match the transistor amplifier to the speaker impedance

A) When the speaker impedance is higher than the output impedance of the power amplifier, there is no other effect except for the different reduction of the output power.

B) When the impedance of the speaker is lower than the output impedance of the power amplifier, the output power is proportionally increased, and the distortion is generally not increased or increased a little. However, the impedance of the speaker should not be too low when matching, like as low as 2 ohms (when 2 4 ohm speakers are connected in parallel), at this time only the power amplifier has a large amount of power, and the high-power tube and multi-tube parallel push-pull with good performance are used. Generally, there is no impact on such a power amplifier.