This circuit produces sounds of 6 different notes depending on the keys activated. The circuit is from a Radio Electronics from May 1965. The transistor must be equipped with a heat radiator.
We found this telephone amplifier in a European publication from the 1980s. The transistor can be...
In figure 1 we have an application for NLAS5113, a new device from on Semiconductor...
We found this circuit in a Popular Electronics from the 90s. Transistors can be modern...