We are building another enjoyable weekend DIY project. This is an audio power amplifier based on LM1876 which can deliver up to 20W per channel into 4 or 8 ohm load and guarantees less than 0.1% THD + N (Total Harmonic Distortion + Noise).
The amplifier is powered by -15 0 15 VAC symmetrical supply. The full bridge diode rectifier and the smoothing capacitors convert the AC input to ±21 VDC which is used to power LM1876. The inductors on the AC input line reduces the noise arising from the mains line.
DIY LM1876 Dual 20W Audio Power Amplifier - [Link]
This article introduces high quality digitally controlled 2.1 channel analog audio power amplifier system. This project is mainly based on TDA7377 AF power amplifier and PIC18F452 8bit microcontroller. Basic technical features of this receiver are covered in table1.
This unit is specifically design to work with PC sound cards, radio receivers and CD/DVD/Blue-Ray players.
Digitally Controlled 2.1 Channel Analog Audio Power Amplifier - [Link]
Voice Module 60 Sec project will playback and record up to 60 seconds of voice message. This circuit is an excellent choice to add voice to your project.
60 seconds Voice Record – Playback module - [Link]
3 Tone Musical Bell is a project built around BT66T (UM66) IC driving, LM386 has been used as audio amplifier to give extra punch.
3 Tone Musical Bell - [Link]
This project is intendant for use as low frequency class AB audio amplifier.
Project is built around TDA2006 PENTAWATT package. TDA2006 provide high output current and has very low harmonic cross-over distortion. Further the device incorporates an original (and patented) short circuit protection system comprising an arrangement for automatically limiting the dissipated power so as to keep the working point of the output transistors within their safe operating area. A conventional thermal shutdown system is also included. The TDA2006 is pin to pin equivalent to the TDA2030.
12W Audio Amplifier - [Link]
Voice Modulator project is designed around HT8950A to provide two special sound effects viz. Vibrato & Robot.
This project provides two special effects: vibrato and robot. The vibrato effect is generated by alternating the frequency of an input signal up and down at a rate of 8Hz. The robot function, on the other hand, converts an input voice into a robot voice. Both effects can be selected depending on which pin is triggered, either ROB or VIB. For the output frequency level shifting, the chips provide seven steps which can be selected from the two groups of pins namely, SW0, SW1 and SW2 for electronic direct selection and ROB, TGD, TGU and VIB for push button selection.
Voice Modulator (Sound Effects) - [Link]
The circuit is built around a popular Sanyos stereo head preamp IC LA3161. Low electrical signals from the playback heads are fed to pins 1 and 8 of IC1 via DC decoupling capacitors, respectively. Components between pins 2 and 3 and pins 6 and 7 provide adequate equalization to the signals for a normal tape playback.
Tape Head Pre-Amplifier - [Link]
This project is a message recording board capable of recording 120 secs of audio. This project is designed around ISD25120 which can store 120 Seconds audio. Recording and playback operations are controlled with tact switches. The kit has an onboard microphone and LED to indicate the functions of Play and Recording. IC has a re recordable non-volatile memory which means that the message will be stored even after the units are turned off and even when it is turned on again.
120 Seconds Voice Record – Play Back - [Link]
Rugged, great sounding boomboxes for all of life’s adventures.
DemerBox is a rugged, great sounding, water-resistant boombox that you can put things inside. The Bang is our single speaker model. Its about the size of a lunchbox but don’t let its svelte size fool you. The Bang gets loud, has tight punchy bass, and pleasing mids and highs. The Big Bang is our two speaker model. Its about the size of a soccer ball. The Big Bang gets louder than The Bang, and because it has two speakers, you get stereo separation and a little more detail in the music.
DEMERBOX – Rugged Wireless Boomboxes - [Link]
Bastl3r wrote this instructable detailing the build of his guitar booster pedal project:
I chose an overdrive pedal design off of generalguitargadets.com (Schematic) and modified it like this:
added a simple positive/middle/negative supply
added a noise filter I found on beavisaudio.com right after the DC Jack (Huminator)
took away the clipping diodes on the output
connected the diodes in the feedback path directly
added the switch to change the resistance of the feedback path (10k <->30k)
Guitar booster pedal (MPX-1) - [Link]