This receiver arose from the desire to demonstrate that valves are fully capable of holding their own against modern semiconductor devices. Valves often have better large-signal characteristics and less noise. The decisive difference is that the circuit must be designed with higher input and output impedances.
This circuit is built using four EF95 (US equivalent: 6AK5) valves, since this type of valve is small and has proved to operate well with low anode voltages. All four heaters are connected in series and operated from a 24-V supply. That makes it attractive to use the same supply for the anode voltage. The achievable gain is fully adequate.
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