Stereo power amplifier which carries a Quarter A circuit.
The Quarter A system is constituted by the input level detector and the fast-switching circuitry,A bias current is fixed and it is considered as a perfect pure Class-A operation, and if fixed power (SM-8 30W) exceeds the power (SM-8 30W-120W), it has a structure automatically switched to AB class operation.
While realizing the power quality which was excellent in the pure Class-A, crossover distortion and a transitional distortion are driven into the minimum also at the time of a high power drive of AB class operation by adoption of a super high fT power transistor, or original Low-TIM design.
Basic circuitry has whole page perfect push pull DC amplifier composition which built in the servo circuitry.
Special resin filling raises thermal resistance to a power-source part, and super audio capacitor 22,000micro-Fx2+20,000micro-Fx2 by which the mass transformer with a compact, and a property and a tone quality were examined are carried in it.
The high heat pipe of the heat-dissipation effect was adopted, and the stable operation of a power transistor is guaranteed also at the time of the Class-A operation which consumes a large current, and the maximum output of AB class.
Moreover, the protection network which detects an excessive output and maintains the power stage in an area of safe operation is carried, and a speaker is driven in the status that it was stabilized.
The logarithmic comression window type peek meter which can carry out the Direct reading of the output of an 8-ohm load intensity is carried in the front panel.
Moreover, in a sub panel, the selector and power switch which can choose the concurrent of a switchpoint and 2 sets of speakers or independent drive which switches the recovery hold time of a meter pointer are equipped.