Tag Archives: LM1875

Audio Power Amplifier with TDA2050


This project is an audio amplifier based on TDA2050 and LM1875.

This is not an ordinary project, but an attempt to make a PCB that is suitable for TDA2050 and LM1875 and has all the necessary circuitry on board – power supply, speaker protection, delayed turn-on and fast turn-off. This is achieved using the convenient uPC1237 IC.

TDA2050 and LM1875 are pin to pin compatible, the differences in their schematics are the values of a couple resistors and one capacitor. All this allows to make an universal circuit board, suitable for any of these two ICs.

Audio Power Amplifier with TDA2050 – [Link]

20W Audio Amplifier


This project is designed to operate with minimum of external components. This amplifier offers high quality and high performance audio at very low distortion. Project is based on nationals LM1875 IC. The IC is thermal and short circuit protected.

The LM1875 is a monolithic power amplifier offering very low distortion and high quality performance for consumer audio applications, the project work on single supply. Device overload protection consists of both internal current limit and thermal shutdown.

20W Audio Amplifier – [Link]

Gobo Stereo Audio Amplifier Kit (LM1875, 15W, Class-AB)


by Giovanni Militano @ diyaudioprojects.com:

I’ve always enjoyed electronic kits of all kind and like many of you will credit them for the foray into DIY audio. Over time as my DIY skills matured I found myself taking the DIY route for projects far more often than relying on kits. While I will always enjoy electronic kits, I generally won’t try one out unless there is something really unique about the kit. When I saw the Gobo Stereo Audio Amplifier kit from boxedkitamps.com, I was immediately intrigued by the unique looking enclosures available with the amplifier kits. Shown in Photograph 1 below is the completed Gobo Stereo Audio Amplifier kit with a translucent blue acrylic enclosure. The choice of enclosure finishes for the Gobo stereo amplifier kit include blue, dark grey and orange acrylic and bamboo.

Gobo Stereo Audio Amplifier Kit (LM1875, 15W, Class-AB) – [Link]

25W Audio Power Amplifier

electronicsimple.blogspot.com writes:

This audio power amplifier project is based on LM1875 amplifier module from National Semiconductor. It is able to deliver up to 30W of power using an 8 ohm load and dual 30V DC power supplies. It is designed to operate with minimum external components with current limit and thermal shutdown protection features . Other features include high gain, fast slew rate, wide power supply range, large output voltage swing and high current capability.

25W Audio Power Amplifier – [Link]

20W Audio Amplifier using LM1875


20W Audio Amplifier kit is based on LM1875 IC.

  • Power supply – 48 VDC
  • Output – 20 W, 4 Ω
  • Very low distortion (THD – 0.015%), good channel separation and ripple rejection
  • IC built-in thermal, short circuit protections
  • Internal output protection diodes
  • Terminal pins for connecting input
  • Power Battery Terminal (PBT) for easy power supply and speaker connection
  • Power-On LED indicator
  • Heatsink for IC
  • Four mounting holes of 3.2 mm each with nut and stud
  • PCB dimensions 48 mm x 60 mm

20W Audio Amplifier using LM1875 – [Link]