This is an improved version of headphone amplifier I`ve built many years ago. I wanted so much to share it with you because this simple circuit has done a great service to me through all these years. It is very simple and reliable, hard to break, offers a lot of power, excellent sound quality, it is built with just a few simple parts and more importantly it has a very little power consumption.
Since I built this amplifier a long time ago I decided to make an improved version now. The schematic has to protections added that aim at the similar purpose. First protection that consists of R4 and C3, simply reduces the noise while turning the amp ON