Found in an 1868 Mullard documentation this circuit has a dynamic range of 10 Hz to 25,000 Hz. Modern equivalent transistors can be used.
This configuration with the 741 Operational Amplifier has an NAB equalization for magnetic...
T1 and T2 can be BC557 and T3 a TIP32 for lamps up to 3 A. The supply is made by voltage of 12 V...
This simple circuit allows testing of CMOS 4001 and 4011 integrated circuits. It consists of an...