The Six's power amplifier adopts an all-stage direct-coupled OCL circuit equipped with two (plus and Minus) power supplies, and in the process does away with coupling capacitor and output capacitors. If you compare this circuit with the conventional power amplifier citcuit using coupling capacitors betwee amplifying stages, you find that the Six has distinct advantages in terms of reduced distortion and a wider power bandwidth. The absence of the output capacitors also prevents degredation of the amplifier damping factor and resultant deterioration of tone quality. The output stage of the power amplifier is apure complementary circuit using NPN and PNP silicon transistos to achieve ideal phase inversion and keep both harmonic distortion and intermodulation distortion minimal at all output levels.

The stability and safety of a direct-coupled amplifier depends upon the effectiveness of temperature compensation and the stable operation of the driver-stage differential amplifier. Included in the Six is a specialized transistor for temperature compensation and a stabilizing circuit used especially for the differential amplifier.In addition, four quick-acting fuses and a newly designed relay circuit are incorporated to protect abnormal current from flowing into your speakers in the event that the power transistor (s) are damaged. Once the abnormal condition is corrected, the relay circuit automatically restores itself. And then it also mutes the pop noise generated when the receiver is switched on or off.

I don’t find much performance on OCL amps on the web. The Sansui Model 6 has OCL amp.


If OCL amps are that good why aren’t there more OCLs out there?

There are... Anything that claims DC in a solid state amp qualifies. So all the Adcoms, Krells, . . . Most recent solid state power amps....

Roscoe