Skema Power Amplifier Built Up Rakitan – Bagi anda yang sudah lama berkecimpung di dunia elektronika pastinya sudah tak asing lagi dengan yang namanya rangkaian amplifier.Bagi anda yang belum tahu, amplifier adalah rangkaian elektronika yang berfungsi untuk menguatkan sinyal.

I've made gainclone amplifier that uses a LM3886 chip. It's one of the best compact HiFi amplifiers. It is a Class AB-A (conjugate) amplifier that has a fully symmetrical structure (push-pull), this mean that the sine waves produced, will produce a +, - output. A 25 volt (+/- Dual Rail), 5 Ampere, toroidal transformer was used to supply electricity for the amp. There's also a PCB Layout provided for the project. I found an old CPU processor attached to a gorgeous heatsink & fan, I recycled both of them and drilled holes for it to be mounted on the LM3886 chips. Specifications: - Maximum Output Power: 68W RMS - 108W Peak - Frequency Response: 7Hz-25kHz (Filtered ⇒Linkwitz) - THD:%0.03 at 60W - SNR: 110dB at 60 W - 92.5dB at 1W - Output Class: AB-A (Conjugate) - Auxiliary Features: DC/AC Short circuit protection and thermal protection.

- Working Voltage/Power: 12-94 Volts (Dual Rail), 1-10 Amperes - Audio Features: Input Mute Funtion (100% silent = no input) Too bad I had a late documentation, that's why I only have a few pictures of the steps and procedures. Due to the late documentation, I had to get images from the source. Some of the pictures are not mine, there are no claims that the PCB designs are mine nor the diagrams, although there where some modifications made by me for the amp. What Is A Gainclone? Back in 1999, relatively unknown manufacturer released the 'Gaincard' to rave reviews.

It immediately caused controversy because it was based around a $5 power amplifier IC (Integrated Circuit), yet a typical setup would cost you around $3300. A Gainclone in the other hand refers to any DIY amplifier that uses a LM3875/ LM3886 as it's main component.

What's So Special About It? The gainclone only uses small amounts of space, it's built with a minimal supply of components, yet giving a great HiFi result. It beats the hell out of those modern HiFi amps, it produces 2x68 watts of power, with a Total Harmonic Distortion of 0.03%THD and built on a 2x3 PCB board! So why doesn't the audio industry use it?

I'm not really sure. All of these sounds 'too good to be true', I recommend this project for those who are still starting on their DIY HiFi amp hobby, since it only uses some few components. What's A Power Amp? A power amp is a amplifier with no preamp, volume control, tone control, or any auxiliary devices attached to it. It's just pure simplicity.

Coming Soon: DIY HiFi Preamp With Tone Control (Works With The Gainclone). I can tell that parts in the US are highly expensive. Here in the Philippines a typical resistor would cost 0.25 centavos ($0.0006), while in america, a typical resistor would cost $1 each. There's a large difference. Also, parts are available here almost everywhere. That's the beauty of living here when you have a hobby of electronics. My project cost me P870.00 ($21.75) all in all. Parts: _______________________________________________ Others: - LM3886 amplifier chip (2pcs.) - 25 Volt, Dual Rail Transformer (Toroidal/ IE) - 2x3 PCB board (2pcs.) - Large Heatsink (2pcs.) - Cooling Fan (1pc.) - Plastic/ Metal Enclosure(1pc.) - AC Cable _______________________________________________ Resistors: _______________________________________________ Capacitors: _______________________________________________.

The LM3886 is the brother of the LM3875. It's the improved version. It produces a higher output wattage, and thermal and mute features are added too.

There are two types of LM3886 IC. One of them is unisolated LM3886T and the other one is isolated LM3886TF. Be careful not to mess with the isolation. LM3886 Gainclone Schematics: (source: ) As you can see, negative feedback line is revised. In this way, about 7dB is gained at 30Hz-70Hz band, and reached about 34db at peak point at 30Hz. When 26v DC supply is applied to the given design, with 4 ohm speaker load and 2Vp-p input signal it gives about 65W RMS power. Kartina solovjevoj tanya ne boitsya moroza.

For users who want to use 8 ohm, we recommend +/- 38V voltage supply. Of course less than this value may be applied too. Supply circuit is shown below, It is simple too. There are two KBU series (6A) bridge diodes and 2x10000 uF capacitors. Calculo larson pdf 9 edicion. As a general rule, 2200uF stabilization capacitor is used per ampere but we are used to use 4700uF per ampere. In our circuit, 2 Amperes will be drawn per line and we use 10000uF capacitors.

We recommend you to use 2x10000uF capacitors per each line if you will use the amplifier in party mode. Dual Rail Power Supply PCB: It's so simple that you don't need to use a custom PCB board, you can use a regular old universal PCB. All you need are four 6 ampere, 50 volts rectifier diodes and two large electrolytic capacitors for filtering (the larger the value the better/ cleaner/less buzzing), 4,700uF is enough to filter the line. Since this is an audiophile setup, I've been using custom winded toroidal transformers. Toroidal transformers has a lesser magnetic flux leakage, this means less buzzing thus you can put the transformer close to the amplifier circuit without hearing any buzzing sound from the speakers/ output. I've placed the capacitors inside the toroidal transformer's core to conserve space (shown in the picture). Here's the PCB Layout of the amplifier.