Class-A stereo power amplifier which adopted the chassis made from die-casting as the radiator made from die-casting.
The Class-A operation is adopted as a whole page.
The Class-A operation sends many idle currents through the transistor also in the time of a non-signal, and is a scheme which uses only operating range with the sufficient linearity of a transistor.
Although a Class-A operation has a low electrical-power utilization factor and calorific value also increases, in order that the upper and lower sides may be amplified by the same wave and may obtain a synthetic output, with B class amplifier, switching distortion or crossover distortion which are not avoided do not generate two transistors of a push pull.
The Class-A operation circuitry of M-22 has DC amplifier composition which removed the capacitor of the NFB circuitry. The time constant formation of the NFB loop was lost by this DC-ization, and the stable NFB operation is realized.
A whole page Class-A operation and this DC amplifier stream composition have realized the mid-high range without a distorted feeling, and the outstanding low-pass property.
The large-sized transformer of a L/R independency and the capacitor of 33,000 micro Fx4 are adopted as a power-source part.
The construction of the whole included amplifier is used as a symmetrical form, and the power relay of a protection network is also using the power-source part by two L/R independencies. Furthermore, attention is paid to leading about of an internal wiring etc. and the cross interferencee between channels is eliminated.
The pure-copper board is adopted as the earth line from an electrolytic capacitor to a speaker termination.
In order to protect a speaker and a transistor even against an emergency outage, the reliable protection network constituted from a quick electronic circuitry of a power relay and a response is built in.
A power relay carries out parallel connection of the two contacts, and is improving the robustness.