Presented here is the schematic diagram of a stereo amplifier boasting a power output of 2 x 60 Watts, constructed around the LM4780 audio amplifier IC developed by National Semiconductors. The LM4780 is an exceptional audio amplifier integrated circuit with the capability to deliver 60W RMS power output per channel when connected to 8-ohm speakers. This IC boasts an impressively low total harmonic distortion, measuring less than 0.5% at maximum output, and possesses a high power supply rejection ratio (PSRR) of 85 dB. It requires minimal external components and comes equipped with a built-in mute feature. Furthermore, the LM4780 is fully safeguarded by National Semiconductors’ proprietary SPiKe technology and boasts a signal-to-noise ratio exceeding 97dB. The provided circuit is ideal for various applications:
- Self-powered speakers
- Home theater systems
- Compact stereos and more
To commemorate the one hundredth design shared on this website and to address the requests of numerous correspondents seeking an amplifier with greater power than the 25W MOSFE. We present a high-quality power amplifier design capable of delivering 60-90 Watts. This amplifier’s circuit topology closely resembles that of the previous design, with the output stage comprised of robust IRFP240 and IRFP9240 MOSFET devices, while the preceding stages feature well-known high-voltage Motorola transistors.
LM4780 pin configuration
- The circuit must be assembled on a good quality PCB.
- The amplifier can be powered using a 35V DC dual supply.
- K1 and K2 must be 8 ohms and 60W speakers.
- An adequately sized heat sink must be fitted to the IC.
The audio Amplifier is the electronic Amplifier that tends to enhance the strength of electronic signals passing through it. It reproduces low-power signals to make them strong enough to drive loudspeakers. For instance, the device receives signals from an electric guitar pickup and then produces a low-power signal to a level that powers the earphones or speakers.