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Sakuma is audiophile who is quite different with any other audiophile with his own unique concept on making tube amplifier. He is considered one of the best tube amplifier master in Japan.

This was article in Remembrance of Sound Past in 1985. In this book, Sakuma introduce amplifier system which use 300B in pushpull mode, working for 2 channel speaker Altec A-5 or A-7. 2 output transformer was used in this system, A-4734 and F-2021.

It is very interesting that Sakuma use power amplifier drive A-288 unit as buffer amplifier for amplifier of woofer515 and as usual, the power tube for woofer is AC heater not DC heater.

Sakuma said :

"The most important goal is not 'Power', but 'Energy' and 'Frame of tone'.
The only way to get Energy and Frame is to mount the many transformers, although I can't tell you a scientific reason for this".

Before him, many people think that using interstage transformer will make sound bad. Almost maker dont use transformer coupling, They use capacitor coupling as instead. About Sakuma amplifier, some say "The Sakuma amplifier is the finest for music listening "; while others say "Judging by his circuit design, Sakuma must not understand audio electronics. His amplifier may destroy speakers".

Sakuma amplfier is very simple, there is very little condenser as well as resistor. All stages are transfomer. As you look at his amplifier, you can see transformer only. Almost transformers using in his amplfiier is Tamura made. He is only one that Tamura provide any transformer he need without fee, for his amplifier That is why the early amplifier made by him using Tango transformer but all later ones using Tamura transformer.

Note : Image was collected in internet.