This circuit from Popular Electronics powers a small speaker. The transistor can be of general use and the capacitors can be altered to change the sound generated.
We found this 4-channel mixer in the August 1999 issue of Electronics Now magazine. The circuit can...
The configuration shown makes use of a simple source and the gain is given by the relationship between R3...
This circuit was found in a 1995 documentation and is very simple to assemble, as the components are...