Here is the "Krill" amplifier published by Steve Dunlap at "Dunlap Audio.
" At 100 WPC, this amplifier stands apart from most 25-50 WPC DIY designs, and it incorporates Steve's special and controversial "Krill" biasing of which there is continued debate. As I was looking for an amplifier with more than 50WPC, this amplifier became of interest since Steve has boards available for purchase, there is a full and detailed parts list, and I was looking for something a little bit different. I bought the parts and boards; and put the design into an old Harmon Kardon AV receiver that was not working. The receiver is very big and so are the Krill boards- they just fit with a little overlap.
Starting Out. 60 Watt Audio Power Amplifier. High Quality, powerful unit: 90W into 4 Ohm load, Also suited as guitar or bass amplifier To celebrate the hundredth design posted to this website, and to fulfil the requests of many correspondents wanting an amplifier more powerful than the 25W MosFet, a 60 - 90W High Quality power amplifier design is presented here.
Circuit topology is about the same of the above mentioned amplifier, but the extremely rugged IRFP240 and IRFP9240 MosFet devices are used as the output pair, and well renowned high voltage Motorola's transistors are employed in the preceding stages. The supply rails voltage was kept prudentially at the rather low value of + and - 40V. For those wishing to experiment, the supply rails voltage could be raised to + and - 50V maximum, allowing the amplifier to approach the 100W into 8 Ohm target: enjoy! A matching, discrete components, Modular Preamplifier design is available here: Modular Audio Preamplifier. GB150D Power Amplifier. The GB150D features my new fully symmetrical discrete power amplifier topology that achieves absolute Hi End performance at low cost.
The design features very high PSRR for reduced sensitivity to power supply quality and the output stage Class AB commutation artefacts superimposed on the supply impedance, which causes the harshness and loss of timbral and spatial detail in lesser designs. The 4 x 150W common source complementary MOSFET output stage swings to within 2V of the supplies, maximizing power output for greater power efficiency than conventional designs, achieving 150W into 8ohms on unregulated +/-55V supplies! The unique topology eliminates the Vas stage which compromises conventional designs, instead employing positive feedback to achieve highly linear and very high first stage gain. Then a complementary 300MHz Class A buffer drives the MOSFETs with only feedback lead compensation for excellent stability with all loads. ExtremA, a reference class-A DIY amplifier. - Introduction.
Despite the fact that class-A operation is rather inefficient, generating lots of heat and requiring a large heatsink there are some compelling arguments in its favor.
One of these is the absence of cross-over distortion, making it a good starting point for designing an amplifier with nearly immeasurable distortion levels. The DIY amplifier presented here offers just that, and can be scaled up to 100-watts in 8-ohm, which should be enough for the majority of applications. So without further ado, lets take a closer look at the design of this amplifier and what it is capable of. Generally speaking there are two methods for setting the output stage bias current of a transistor amplifier to guarantee sufficiently low distortion levels. One is "optimal class B", a setting where the transconductance of the output devices at idle is the reciprocal of the degeneration resistors. DIY 40W MOSFET AMP. DIY Amplifier gets new DIY Power Supply. I like this delay timer as it counts AC mains cycles for the delay.
The timing chart shown is for 50Hz mains. Caution - as drawn, it is directly powered off the mains, but it should be simple to power it off a lower voltage tap (6V ac, for eg) and use a relay of the appropriate voltage. DIY 25 W Class-AB Power Amplifier. Updated 00-08-07 25 W DIY Power Amplifier Try something simple for a change When you look at DIY constructions of amplifiers, it's often large expensive designs!
Why not try something simple for a change?
Diy Class-A mosfet amplifier A-75. A75 Class-A MOSFET Amplifier, Design by Norman Thagard and Nelson Pass RE construction by Gus This is a lovely sounding amp that has really underscores my need for a better set of loudspeakers.
It was fun to build. Like this: Like Loading... Jean Hiraga. DIY and Hi-Fi Audio Schematics. DIY AUDIO PROJECTS - Do-It-Yourself Hi-Fi for Audiophiles. HPA-nxV300 380 watt MOSFET Audio Amplifier Module. Introduction to the HPA-nxV300 R2 amplifier module.
The nxV300 R2 audio amplifier module is based on the high performance nxV500 R2 module. Unlike the nxV500 which has eight Toshiba output devices this version has four high performance Toshiba MOSFET's in it's output stage. Making it a much more compact but no less powerful. Boasting a power output of around 220 watts RMS into 8 Ohms and 380 watts RMS into 4 Ohms. It also has XLR Balanced input which can be easily configured for RCA or unbalanced input. Basic Audio Power Amplifier Design by AmpsLab.
Doug Self. Simple cost effective darlington amplifier. This amp had its genesis in the Widlar (pronounced Widelar) circuit below published in the LM308 application note of 1969 The op amp deliberately has a low resistance load R3 and R4 which means a useful current flows into or out of the transistor bases.
The current is amplified by Q1 and Q2. Note the only connection between the op amp output and the actual output is a feedforward capacitor. There is no provision to set the bias for Q1 and Q2 so there will be crossover distortion. I thought why not use a respectable op- amp and a pair of darlingtons to make a hifi amp. Steph on the Diyaudio site came up with a model of the Ne5534 op-amp which I am using as the basis of a simple power amp also using BDX33 & BDX34 darlington output devices. Interesting letter on this from the late Les Sage (my fellow author in the Audio Conversions magazine of the 90’s) The NE5534 dates back to 1978, interesting comparison here with the LM318: if you thought Paul’s site covered all the topologies try this:
Nelson Pass. Ben Duncan. JLH. LME49830TB Ultra-High Fidelity High Power Amplifier Reference Design (Rev. B) - snaa058b. Initial Series. Planet Analog - Articles - Integrated 200V audio driver packs power in small footprint. Compact Series. COMPACT Series Compact series amplifiers are designed and optimized to provide high-quality, low-distortion output up to 60 W into 8 Ohm.
They are all-in-one, single-board amplifiers suitable for novice audio DIYers. LME49810, LME49811 with ThermalTrakTM Amplifier Discussions on diyAudio forum THD + N vs output power FFT of 19 + 20 kHz at 80 W peak into 8 Ohm Compact 4981x ThermalTrak Amp rev 2.1 schematic Compact 49810 ThermalTrak Amp component list Compact 49811 ThermalTrak Amp component list Shopping Our Packaging for boards We pack the boards carefully in order to have them in excellent shape on you hands.
Each board is covered by protective foil. They are further protected by bubble bags. LME49810 Audio Power Amplifier Driver with Baker Clamp. Overview Basic Features National Semiconductor introduced the LME49810 integrated circuit in May 2007. There was an official news release made on 23rd July 2007. Мой фотоальбом. LME49810. LME49810 Top Audio Power Amplifier Kit Board Mono 300W. D h m s day hour hours FREE shipping See item description Approximately: Speaker Amplifier and Modulator - Mid/High-Power Amplifier - LME49810. Description.
Headphone Amplifier - Aune X-60 Stereo Amplifier 2x60W LM4780 8 ohms kit. Custom amplifier, amplifier module, high voltage amplifier, MOSFET amplifier, piezo amplifier. Power Amplifiers Laboratory, Audio, Modules, Custom Industrial/Laboratory. Gainclone 2. Synergy - a LM3875 Gainclone Amplifier (Chip Amp)
Class A. Class-A Amplifiers explained. Amplifier Classes. Class A Amplifier - Transistor Amplifier Tutorial. Power Amp Kits by AmpsLab. 2 X CLASS A POWER AMPLIFIER KIT - BASED ON MF A1! DIY Stereo Audio Power Amplifier Kit fr QUAD405. Postage to: Europe. Audio:Sounds Good to Me! The Class-A Amplifier Site. Plamen Todorov's DIY Blog. Class D. Audio Amplifier Kit - for lower prices order online through Pricedumper.co.uk.
OPA541 Parts Placement Guide and PCB Foil Pattern. Leach Low TIM Power Amplifier Version 4.5 Probably one of the most celebrated power amplifiers in the web, especially to DIY enthusiasts all over the world. This amp has a very colorful history and has been updated several times since it's introduction but still resembles the first version of the amp in many ways. Thanks to it's designer W. Marshall Leach, Jr. for making this excellent amp available to everyone in the planet. You can find detailed plans and other interesting articles at Mr. My finished and working Leach amp... Output transistors are ON Semiconductor's MJ15024/25 pair...
A Chassis shot showing the whole layout... The 44V-0-44V/10A power transformer... The 35A bridge diode, ELNA 10,000uf per rail supply capacitors, bleeder resistors, snubbers and lots of decoupling caps all around. The input signal-in/overload indicator... The clipping indicator (behind the trafo)... The speaker protector with turn-on delay and dc protection... Now isn't that a beauty? Hosting by WebRing. Audio:Sounds Good to Me!