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.
50W Power Amplifier with LM3886 – [Link]
In this episode Shahriar presents a tutorial on the design and characterization of a single-stage low-noise bipolar amplifier suitable for audio applications. Given a set of specifications, a common-emitter topology is investigated. The circuit employs a beta-insensitive biasing scheme which is simultaneously optimized for maximum output swing. The small-signal gain of the circuit is calculated and the bandwidth is set for audio frequencies. A non-inverting operational amplifier is used as a second stage to achieve the desired overall gain. The circuit is assembled on a breadboard where the gain and bandwidth are measured and compared with design specifications. As the final experiment, the circuit is used to amplify signals from a microphone.
Tutorial on the Theory, Design and Characterization of a Single Transistor Bipolar Amplifier – [Link]
by Roy McCammon:
The traditional three op-amp differential amplifier’s signal to noise ratio can be improved by 6dB by adding a resistor and slightly changing the connections. There is a trade-off though: The traditional topology has a high input impedance, whereas the low-noise version has a lower input impedance.
Differential amp has 6dB lower noise, twice the bandwidth – [Link]
by University of Bristol:
A breakthrough in the design of signal amplifiers for mobile phone masts could deliver a massive 200MW cut in the load on UK power stations, reducing CO2 emissions by around 0.5 million tonnes a year.
Funded by the Engineering and Physical Sciences Research Council (EPSRC), the Universities of Bristol and Cardiff have designed an amplifier that works at 50 per cent efficiency compared with the 30 per cent now typically achieved.
Currently, a 40W transmitter in a phone mast’s base station* requires just over 130W of power to amplify signals and send them wirelessly to people’s mobiles. The new design, however, enables the transmitter to work effectively while using just 80W of power.
New design for mobile phone masts could cut carbon emissions – [Link]
w2aew @ youtube.com writes:
A tutorial on the basics of an inverting and non-inverting summing amplifier using an op amp. The video assumes a basic knowledge of how inverting and non-inverting amplifiers using op amps work. If you are unfamiliar with this, I’d recommend viewing my video on how to easily understand the operation of most opamp circuits: https://www.youtube.com/watch?v=K03Rom3Cs28
Basics of an Op Amp Summing Amplifier – [Link]
This 1w audio amplifier circuit is designed using NCP2830 audio IC manufactured by ON Semiconductor. This audio power amplifier ic designed for portable communication device applications and require few external electronic components. NCP2830 is capable to provide 1W continuous output power in 8 ohms load. NCP2830 audio power amplifier main features are : high quality audio (THD+N = 0.04%) , low noise: SNR up to 100 dB, overall system efficiency optimization: up to 89% , Superior PSRR (−88 dB): Direct Connection to Battery , Very Low Quiescent Current 7 mA , Optimized PWM Output Stage: Filterless Capability , Selectable gain of 2 V/V or 4 V/V .
1W audio amplifier circuit using NCP2830 – [Link]
This DIY 300B triode amplifier project was completed by Stamou Tasos who is from Greece. Giovanni Militano and Stamou Tasos write:
As a thank you for the 300B amplifier schematics, Stamou has shared with us his implementation of the 300B single-ended (SE) tube amplifier schematic by J.C. Morrison. I have assisted by translating, formating and presenting his DIY 300B triode amplifier project.
The circuit that I decided to follow for my 300B triode amplifier I found on this site, the 300B Single-Ended (SE) tube amplifier schematic with direct coupled 6SN7 input stage. Please take a look at the SE 300B schematic for a description of Mr. J.C. Morrison’s SE 300B tube amplifier circuit which I will refer to as the “original schematic”. Specifically recommended in the circuit notes was that premium output transformers and components be used for the 300B amplifier build. For this SE 300B triode tube amplifier build I have used premium parts throughout, Lundahl audio output transformers and a DIY chassis. This 300B Single-Ended-Triode (SET) amplifier circuit uses a direct coupled 6SN7 driver stage. The output stage is a SE 300B triode and the maximum power output is about 8 Watts per channel. A pair of reasonably sensitive (~91 dB+) loudspeakers will be required with this 300B SET amplifier.
DIY 300B Single-Ended-Triode (SET) Hi-Fi Amplifier – [Link]
Industry’s Widest Range Current-Sense Amplifier Measures 10mA to 10A without Increasing Measurement Errors
The MAX44284 is a high-side, current-sense amplifier that operates with a 1.7V to 5.5V single supply and is optimized for very low power operation with only 21µA of quiescent current.
The MAX44284 offers precision accuracy specifications of 2µV VOS and gain error of 0.05% (max). The device features an input common-mode voltage range from -0.1V to +36V. This current-sense amplifier has a voltage output and is offered in four different gain versions.
MAX44284 – 36V, Input Common-Mode, High-Precision, Low-Power Current-Sense Amplifier – [Link]
Make your own computer speaker system. This simple and inexpensive project will let you set up a small audio amplifier circuit and let more sound out your computer.
A simple audio amplifier circuit based on the LA4440 IC. This circuit will take your computer’s headphone level output and amplify it to drive a pair of external speakers. If you are listening to music or movies on laptops and computers, this is a useful little project for you. Laptop speakers are never loud enough to give satisfying listening. They give users the ability to hear something, but for anything like music or movie soundtracks they are very poor performers. The output from a laptops built in speakers is just too low, and this circuit addresses that low power with some additional amplification.
This circuit uses an LA4440 and some supporting components to give you much more power, while retaining a small package that you can use. The LA4440 is a dual channel audio power amplifier, with low distortion, and a good frequency range. Using 2 channels, the LA4440 will output 6 watts per channel, that can drive much larger speakers than a laptop can hold. When you set up a small enclosure(s), a 12V power supply, and an audio jack connection to the laptop you’ll have a nice enhancement to your laptop audio enjoyment.
Laptop Audio Amplifier – [Link]