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.
Found in a Popular Electronics from the 90s, this circuit operates up to about 5 MHz input....
This circuit was found in a 1987 edition of the United States' Hands-On Electronics magazine. The...
This circuit that uses potentiometer tuning, was found in a documentation from the 80's. The...