Gert of KGELABS posted a step by step guide of his DIY small stereo amplifier: This project started after getting an old schoolproject from a friend. A metal chassis with a single ECL86 tube, a power transformer and a small Muvolett (Amroh) 7044 output transformer. Intrigued by the simplicity of this amplifier I decided to rebuild the amplifier […]
Dilshan Jayakody writes: SL414 is combined audio preamplifier and power amplifier IC manufactured by National semiconductors in early days. This amplifier is designed to operate in 10V to 20V range and deliver 3W (R.M.S) audio output power into 7.5Ω load. The frequency bandwidth of this IC is between 30Hz to 18kHz and with 8Ω load […]
Semelab’s application note on lateral mosfet design recommendations for audio amplifiers: Semelab’s range of lateral mosfets has been specifically designed for audio power amplifiers and there are a number of advantages that they exhibit over bipolar transistors in these applications. This application note is intended to highlight these differences and give design guidelines in using the mosfets for […]
An article on a DIY 30 watt stereo amplifier circuit by Ron Hoffman over at Gadgetronicx: The Stereo Amplifiers are quite handy in places where we need to amplify the input signals to make it audible for all. Weather it was a party or a simple meeting, this thing will do a perfect job in there. This […]
Another project from Rajkumar Sharma of Electronics Lab a 5W Stereo Audio amplifier based on BA5406: 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, […]
A voice echo module with build-in amplifier project by Rajkumar Sharma of Electronics Lab: 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 […]
An app note on Gamma-photon radiation detector (PDF!) by Maxim: A PIN photodiode, four low-noise op amps and a comparator are used to detect individual photons of gamma radiation. The schematic, design considerations and component selection are discussed.
An old but interesting app note (PDF!) from Linear on high speed amplifier techniques: Most monolithic amplifiers have been relatively slow devices. Wideband operation has been the province o discrete and hybrid technologies. Some fast monolithic amplifiers have been available, but the exotic and expensive processing required has inflated costs, precluding widespread acceptance. Additionally, many of […]
An audio power amplifier based on LM1876 from Electro Labs: 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 […]
Dilshan Jayakody writes: 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 features of this receiver are 2 × 6W + 20W audio output power, ±14dB bass and treble controls, fully configurable +35dB bass booster […]
Rupert Hirst writes: A long awaited refresh, to my previous “Anti Thump” headphone output delay circuit, designed back in 2011. The Idea behind the circuit is to introduce a small delay, during initial power up, to electrically isolate and protect equipment connected directly to an amplifier. Often, during power up, amplifiers can produce an audible […]
Ethan of Protofusion designed and built a stereo vacuum tube amplifier based off of the TubeLab SimpleSE design.
Chris Holden writes: Steve Carpenter wants some wav playing boards, so I redesigned the circuit to use an integrated op-amp, so they just require power and a speaker. I’ve no idea which op-amp works best, a TL072 or an LM386 (I’ve not had much luck with the LM386 in the past, and Steve really rates […]
Dilshan Jayakody writes: This is high quality audio power amplifier which we constructed for our audio related experiments. This amplifier is based on NXP’s TDA1521A integrated circuit and it is capable to deliver 2 × 6W audio output power with 20V – 25V asymmetrical power source. The design of this power amplifier is heavily based […]
Jeff of MightyOhm writes: Tony Long and I designed and built a 24 GHz low noise amplifier for our ECE192 undergraduate independent study project at UCSD. The amplifier was designed with an early version of Agilent ADS, PCBs were fabricated on Rogers 5880 (Duroid), and we hand built several prototypes on K-connector fixtures that Tony designed. Measured […]
Paul over at Dorkbotpdx writes: Recently I needed to actually “see” a current waveform in the 100 uA to 5 mA range with at least a couple MHz bandwidth. This extremely expensive probe would have been perfect, but instead I built something similar for about $30 using the amazing Analog Devices AD8428 amplifier.
Dilshan Jayakody has written an article about his open hardware project known as Smart Audio Box (SAB): Smart Audio Box (SAB) is microprocessor controlled audio switch and amplifier system, which is specifically design for audio composers and for audio engineers. SAB consist of 4 high impedance stereo inputs and two output modes. One output mode […]
An app note from Analog Devices: Build precise S/H Amps for fast 12 Bit ADCs (PDF!) S/h amplifier circuits will use one of several standard architectures: closed-loop or open-loop, and inverting or noninverting configurations. No matter what circuit type designers employ, they need to incorporate a high-speed amplifier to buffer the input signal and a […]
Paulo shared an Excel-based transistor amplifier calculator. ‘Besides the basic gain and biasing calculations many others implement, this calculator can also estimate noise which is a bit more involved’: ..Because this is a circuit I use frequently, I decided to make an Excel spreadsheet to ease the calculations. The spreadsheet started as a simple resistor […]
Jason has been working on a portable software defined transceiver design for the past year. Every day this week he’ll discuss a different part of the hardware in a series of guest posts. You can chat with the designer in the forum. Today’s post is about the power amplifier. Since this project is designed for […]