| Schematics >>
Audio / Amplifiers
60W Power Amplifier
This is a simple and low cost 60W power amplifier. The optimal supply voltage is around 50V, but this amp can work from 30 to 60V. The maximum input voltage is around 0.8 - 1V. As you can see, in this design the components have a big tolerance, so you can build it with almost any components that you can find at home. The output power transistors can be any NPN types, but do not use Darlington types.
Stereo Headphone Amplifier
This is an improved version of headphone amplifier I've built many years ago. I wanted so much to share it with you because this simple circuit has done a great service to me through all these years. It is very simple and reliable, hard to break, offers a lot of power, excellent sound quality, it is built with just a few simple parts and more importantly it has a very little power consumption. With just two AA batteries it can work for a very loong loooong time.
μAmp Miniature Audio Amplifier
The small AF amplifier Suitable for laptops and MP3 players. IT may be powered from the PC (Game or USB) or AC adapter.The basis of the amplifier is an integrated circuit TDA2822M. With this circuit you can build an amplifier with output up to 2x 1 W. This high power circuit is only able to supply at peak times, when excited, would be permanently unable to work. Involvement of the amplifier is to figure 1. The input signal passes through frequency-dependent volume control on the divider. Frequency-dependent divider produces frequencies around 100 Hz, with a positive influence on the subjective sound quality when using small speakers. IO is the involvement of manufacturers' recommendations. The amplifier output can connect speakers with an impedance of 8 ohms (or greater), or headphones. IO supply voltage can be in the range of 1,8 to 15 V. The low supply voltage power amplifier is very small, at high supply voltage and load speakers with low impedance circuit may be a little overheated. With 8 ohm speakers are suitable voltage in the range of 6-9 V. I used to supply voltage 5 V, which are derived from the game port. Voltage of 5 V can be obtained even from the keyboard connector, PS / 2 port and USB. A better option is a network adapter, there are no problems with earth loops.
10-14W Class A amplifier
I have built this amplifier and it does sound good. It requires a preamp as it hasn't got much gain. It requires big heat sinks and a large transformer and a great power supply and careful wiring, but in the end it is extremely simple and it sounds very good. The zener diode rejects any ripple coming from the power supply, But you still only want a ripple of 10mV max. The ripple reaching the input is amplified, so the zener gets rid of that, but whatever ripple there is will still reach the power stage.
100W Car Subwoofer Amplifier
Complete car amplifier for subwoofer based on TDA7294 amplifier chip. This is a much powerful than previous TDA1562 based version (LINK), but its based on push-pull converter so its more difficult to build. Build-in low-pass filter, all on one one-sided 75mm x 125mm dimension PCB.
100W HI-FI MOSFET Amplifier
Here is a simple 100W HI-FI MOSFET Amplifier.
The main feature of this amplifier is a simple design and assembly. Simplicity of the circuit by looking at the circuit you expect amplifier to be simple. It should be noted that many hi-end amplifiers have a very simple but good quality designs. General technological theory is due to fewer parts, fewer problems. Additionally power to supplement your system is quite effective. Power supply transformer is very important. 8 Ohm output for a 35 - 0 to 35 V and at least 3 amps per power amplifier is recommended that a transformer can be transferred. Naturally, the two substations will be required for stereo use.
100W HiFi MOSFET Amp
The neat thing about the series 5000 is that it was built around new (at the time) Hitachi lateral power MOSFETs. Most power MOSFETs (VMOS, trenchFETs, HexFETs etc) use a vertical structure, where the current flows vertically. This has the advantage of stunningly low Rds and hence high efficiency, but does nothing for linearity or capacitance. Lateral MOSFETs are a much simpler structure, where the gate oxide is formed on a flat substrate, and the current flows across the substrate. This results in well defined, controllable device parameters, good linearity, and relatively low gate capacitance. However, the Rds of lateral MOSFETs is nothing to write home about.
100W LM3886 Power Amplifier
This is 100W LM3886 power amplifier is based on the PA100 parallel amplifier detailed in National Semiconductor's application note - AN1192.
Since my DIY speaker is 4-ohm and somewhat difficult to drive, I want to have a more powerful amplifier to match with it. Therefore I designed this amplifier which uses two LM3886 per channel, in parallel circuit. This amp can deliver about 50W into a 8-ohm speaker and 100W into a 4-ohm speaker. This is a stereo amplifier and therefore 4 LM3886s are used. The LM3886 circuit is in a non-inverted configuration, so the input impedance is determined by the input resistor R1, i.e. 47k. The 680 ohm and 470pF resistor capacitor filter network is used to filter out the high frequency noise at the RCA input. The 220pF C4 and C8 capacitors are used to shot out the high frequency noise at the LM3886 input pins.
I used high quality audio grade capacitors at several locations: 1uF Auricap at the input for DC blocking, 100uF Blackgate for C2 and C6, and 1000uF Blackgate at the supply filter.
100W Power Amp
This is a 100W Transistor based Power Amp Circuit. It's an old circuit, but nice circuit amplifier. Uses transistors MJ15003 and MJ15004, power supply +38V,-38V 3A.
Output power is 100W for 8 OHM Speaker.
12AU7 Tube Preamplifier
I'm not sure what motivated me to decide on building a high-gain tube preamp of this sort. Maybe it was the tube computer sound card idea I have seen, or the fact that I have enough junk to fill a dump truck. What ever it was, it all started with a cute little plastic Hammond enclosure that had been on my shelf for a couple of years. I originally thought I might use it for a tube headphone amp, but in the end realized there would not be enough space for the three tubes needed to make a head amp. This is a high gain preamplifier that is suitable for use where a lot of gain is required - to drive a power amplifier that needs plenty of gain or perhaps for use with instruments, like a guitar or microphone. If you need less gain, take a look at the RCA 12AU7 / ECC82 Cathode Follower Tube Preamp Schematic which has a gain of about 8.