This interesting transistor circuit has several effects and an included amplifier. The circuit is monophonic and powered by standard batteries. The number of keys can be changed.
This circuit was found in a Popular Electronics from the 90s. The frequency depends on the...
This circuit consists of a “zero crossing detector” that provides a rectangular output signal...
Low power RF transistors such as the BF494 or BF495 and even those in the BC series can oscillate well...