Sorry, that's 2SK77's.

Best Regards,

Gary

If you check into the Journal of Audio Engineering Society vol. 8 for 1960 you can read about a "Signal Biasing Amplifier" designed by Richar Heyser and patented by Cal Tech. His amplifier was about the same power as the SIT amp and without output transformer also. Dick gave a talk at TRW Laboratory that year using his amplifier built into a package about the size of a cigarette pack that was held in his shirt pocket. The amplfier was used as his P.A. amplifier. Later in the talk he also showed that a closed circuit video could be played through the same amplifier since the bandwidth was better than 4 mHz. I spoke at the same meeting describing an early germanium transistor amplifier that was sold under the name of TEC (Transis-Tronics). The same design was sold also with slight styling changes by Olson Electronics, The Knight Div. of Allied Radio, Lafayette Radio, and Radio Shack. Those were the "Good Ol' Days" when everything was new. Russ Allee

Part Deux shouldn't be far off.

But, it's not what you think it is.

Yes, that's a standard polarized electrolytic capacitor.
The output is at +20V or so, so you need to observe the correct polarity.
You could use a NP cap (if you can find one that big). You could also bypass the output cap with your favorite fancy film cap.

certainly