Schematic Diagram 4in1: 100W RMS Power Amplifier With VU, Power Supply and Tone Control

Part Lists

Active Components

• IC TDA 7294 : 1
• IC 7812 : 1
• IC LM3914 : 1
• Diode Zener 12V : 2
• IC 4558 : 1
• Diode 1N4148 : 1
• Rectifier Bridge Diode 6 A : 1
• LED : 11

Resistors

• 390 Ω – 1/4w : 1
• 680 Ω – 1/4w : 1
• 1K Ohm – 1/4w : 2
• 2k2 Ohm – 1/4w : 3
• 2k7 Ohm – 1/4w : 1
• 3k3 Ohm – 1/4w : 1
• 5k6 Ohm – 1/4w : 1
• 8k2 Ohm – 1/4w : 1
• 10K Ohm – 1/4w : 4
• 20K Ohm – 1/4w : 2
• 22K Ohm – 1/4w : 3
• 30K Ohm – 1/4w : 1
• 47k Ohm – 1/4w : 1
• 10R ohm – 1/4w : 1
• 56R Ohm – 2w : 1
• 2K2 Ohm – 2w : 2
• Potensiometer 50K Ohm : 3

Capacitors

• 100pF nonpolar capacitor disc / ceramic : 2
• 6n8F nonpolar polyester capacitor : 2
• 10nF nonpolar polyester capacitor : 2
• 100nF nonpolar polyester capacitor : 6
• 220nF nonpolar polyester capacitor : 1
• 2.2uF/63V electrolytic capacitor : 1
• 10uF/63V electrolytic capacitor : 5
• 22uF/63v electrolytic capacitor : 2
• 100uF/63V electrolytic capacitor : 2
• 4700uF/63V electrolytic capacitor : 2

100W RMS Power Amplifier PCB Layout

Component Placement

This is a single channel (mono) audio system. For stereo audio system, you need two similar circuit and make some changes such as: use higher transformer current, higher diode current, higher capacitor value for the power supply module. Use only one power supply. Use stereo potensiometer and connect to the two boards using cable.

In this 100W power amplifier circuit, the two of LM3886 are paralled to gain more powerful amplifier output. This amplifier can deliver about 50W into a 8-ohm speaker and 100W into a 4-ohm speaker. To make a stereo amplifier, there are should be use 4 pieces of LM3886.

The LM3886 is a high-performance audio power amplifier capable of delivering 68W of continuous average power to a 4O load and 38W into with 0.1% THD+N from 20Hz?20kHz. It can be used for general purpose application such as Component stereo, Compact stereo, Self-powered speakers, Surround-sound amplifiers, High-end stereo TVs etc.

The documentation of this 100W amp project: http://www.shine7.com/audio/pa100.htm
Visit the page to get information about schematic diagram, PCB layout and construction information.

Download the LM3886 datasheet for circuit reference from below link:

LM3886 Datasheet

1 file(s) 1.15 MB

Download Datasheet

The circuit should be seen like this:

This is an exceptionally well designed amplifier, with a lot of power reserve, high fidelity, low distortion, good S/N ratio, high sensitivity, low consumption and full protection. Having all these almost ideal characteristics this amplifier is likely to become the basic building block of your future high fidelity system, or it can also become the element that will upgrade your existing system.

Schematic diagram:

Component part list:

PCB Layout:

Component placement:

Technical Specifications:

Output power (f=1 KHz, d=0.5 %): 100 W in 8 ohm
Supply voltage: ……………. ?? 40 V
Quiescent current: …………. 50 mA
Maximum current: …………… 2.6 A
Sensitivity: . 600 mV
Frequency response: ………… 10-35000 Hz (-1 dB)
Distortion HD: …………….. 0.01 %
Intermodulation dist.: ……… 0.02 %
Signal/noise: 83 dBConstruction

Go to this page for detailed explanation.