What is the TWO channel amplifier?

The adjustment of crossover networks is annoying to users of multiple-driver loudspeaker systems.
All audiophiles know that every LP and CD requires optimization of the crossover. Every kind of music can benefit this way.
By the time the experimenting audiophile finds the best compromises in adjustment he may be weary in body and mind.

Mr. Sakuma found a simple way to avoid this fruitless effort.
First he tried to control a two way speaker with TWO amplifiers.

The network-1 kept low frequencies from the tweeter and the network-2 kept high frequencies from the tweeter.
Soon he found a better method. He built two amplifier units on one chassis.