Circuit diagram of 70W OCL power amplifier

This is the circuit diagram of the 70W OCL power amplifier with an output power of 70 watts mono. It uses power transistors TIP2955 and TIP3055 as its main components. The power supply used by this amplifier is a symmetrical/bipolar supply with an output voltage of 25V–32V. This amplifier can be used to drive 4-16 ohm speakers. For a stereo system application you will need to make two similar circuits and power them with a 5A transformer.

What is an OCL amplifier?

An OCL amplifier (Output Capacitorless Amplifier) ​​is any audio amplifier with a directly coupled capacitorless output. Generally, OCL amplifiers can be any of several amplifier classes and usually have a push-pull output stage (Wikipedia).

The advantages of OCL amplifiers over capacitively coupled amplifiers include:

Avoid the cost and size of output capacitors

Better resistance to jet ski vibrations

Greater output power at very low frequencies and DC