A USB DAC designed using a TI PCM2707:
it was a very fun project and very fulfilling to make something that I actually use everyday. Overall the audio specs aren’t anything amazing, but it definitely is an improvement on the built in audio of my computer.
DIY USB DAC - [Link]
by George Gardner @ georgegardner.info:
This is a project that I’ve been working on for some time now, a good part of my life, but more recently for the past month. I’m not going to go through everything as to how I arrived at this point, but I can assure you it was through a lot of trial and error. I now present to you, the class D avr amp.
Class D AVR - [Link]
This is my second encounter with LM3886. I was pleased of the sound this chip produced the first time, so I decided to make another amplifier with it. The schematic is based on the schematic in the datasheet of the chip with minor changes.
I removed the time delay capacitor connected to MUTE pin, because it’s better to use separate DC protection schematic which has similar functionality. I made the output inductance L1 by winding 15 turns of enameled wire around the resistor R7. The diameter of the wire must be minimum 0.4mm. The whole was wrapped with heat shrink. I used 47uF/63V non polarized capacitor for C2. It can be regular electrolytic capacitor, but it’s better to use non-polarized or bipolar.
50W Power Amplifier with LM3886 - [Link]
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]
5W Stereo Audio Amplifier project based on BA5406 IC which is suitable for application like stereo radio cassette player, stereo components systems etc.
The Heart of the project, BA5406 is a dual OTL monolithic power IC with two built-in, high output speaker amplifier circuits. High output of 5W×2 can be produced when VCC=12 V and RL=3Ω, and 2.8 W×2 when VCC=9V and RL=3Ω. The BA5406, which uses a high allowable power dissipation package, has a simple heat-sink design.
5W Stereo Audio Amplifier - [Link]
by Rob Matheson @ phys.org:
Stream video on your smartphone, or use its GPS for an hour or two, and you’ll probably see the battery drain significantly. As data rates climb and smartphones adopt more power-hungry features, battery life has become a concern. Now a technology developed by MIT spinout Eta Devices could help a phone’s battery last perhaps twice as long, and help to conserve energy in cell towers.
Beating battery drain: Power-conserving chip may increase smartphone battery life - [Link]
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]
A project has been designed around Holteks Ht8970 voice echo IC. Project can be used in various audio systems karaoke, toys, animatronics, show, display, exhibitions, and sound equipments.
The HT8970 is an echo/surround effect processor. It is designed for various audio systems including karaoke, television, sound equipments, etc. The chip consists of a built-in pre-amplifier, VCO or Voltage Control OSC, 20Kb SRAM, A/D and D/A converters as well as delay time control logic.
Voice Echo - [Link]
by Barry Harvey @ edn.com:
We analog designers take great pains to make our amplifiers stable when we design them, but there are many situations that cause them to oscillate in the real world. Various types of loads can make them sing. Improperly designed feedback networks can cause instability. Insufficient supply bypassing can offend. Finally, inputs and outputs can oscillate by themselves as one-port systems. This article will address common causes of oscillation and their remedies.
Does your op amp oscillate? - [Link]
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]