This is Electronic Stethoscope circuits. Usually the stethoscope is a medical device that listens to the heartbeat. Which we can make it with the least amount of electronic equipment so easy to make.
The simple low voltage preamplifier circuit for headphone with tone control that use 1.5V X 2.The transistors as main. For MP3 player or other small source.
We will use Class A headphone amplifier circuit that is very good quality sound. Consists low noise Op Amp ICs and 2 transistor as main so have very cheap [...]
Two circuits of Hifi transistor headphone amplifier!