This 1924 receiver uses a battery for the tube filaments and a high voltage battery for the amplifier and detector circuit. The speaker is kind of high impedance era.
This circuit was found in February 1976, Radio Electronics magazine. The components are from the...
Analog Devices AD7768 24-bit sigma-delta (Σ-Δ) ADCs include an Σ-Δ modulator and digital filter...
We found this circuit in Linear Technology Applications 1993. The maximum output current is 5 A...