A music synthesizer is Frank’s entry to the 555 contest. He used a 555 timer to make a really cool synthesizer that is played with a stylus and has filtering and volume enveloping features. Various note frequencies are generated with precisely calculated resistances. [via]
555 Contest Entry: Music synthesizer – [Link]
Today we did an project amplifier with LM386. This amplifier is very easy to make and very compact, works with a single power source whose value can be between 4V and 12V.It is based on the use of a type LM386 amplifier, capable alone to issue a power of several hundreds of milliwatts to a load (HP) of 8 ohms, while consuming only a few mA at rest. Ideal for make a small portable battery powered amp.For an application in stereo, just to build this amp in two examplaires.
Amplifier With LM386 - [Link]
Makerdino shares his 555 Slider Synth: [via]
When it’s turned on by pressing SW1, the 555 astable oscillator is activated. It will produce a tone through the speaker that can be varied in pitch by changing the distance between the LED and the photo cell.
The 555 SliderSynth – [Link]
One of the applications of 555 timers is a class D amplifier. In its most simplistic form it can be built with a single 555 and the 200mA current capability is enough to drive a small speaker, making it a good replacement for a low power amplifier. But I wanted more; I wanted to use it to build an amplifier that had enough power to allow listening to music in a small room. Adding a high power stage to a classical 555 class D amplifier was too easy, so I decided to build my own high power 555.
555 class D amplifier - [Link]
Here’s a Leach Amplifier based on 2SC5200 and 2SA1943 output power transistors that can provide up to 700W of power. The mechanical design is relatively simple, the transistors are placed on the two cooling profiles with a height of 66 mm, width 44mm, overall length 260mm. They are turned against each other Thus, from the cooling tunnel. Coolers are attaching the nylon backing which allows the assembly of transistors without washers, and thus better transfer of heat. DPS amplifier is at the top of the tunnel and the transistors are soldered from the bottom of PCB.
700W Leach Amplifier – [Link]
The amplifier design includes not only the final stage of the source (rectifier, filter) and protection against DC voltage output amplifier and speaker connections delayed. As already mentioned, the amplifier is designed as a single-module. This means that on one common board rectifier, filter capacitors, protection And definitely amplifier. Regarding the components of the external solution, the solution based on the original Mr. Marshall Leach.
275W Leach Amplifier – [Link]
After I built several LM3875 and LM3886 gainclone amplifiers, I was totally impressed by their audiophile sound quality. My design goal is to create a audio power amplifier that can deliver 300W into my 4-ohm DIY speaker with low distortion. I want it to produce deep, tight and punchy bass while keeping the excellent mids and highs from my other gainclones. My design uses a PCB to hold 3 paralleled 3886s (i.e. PA150), and then I use the DRV134 to bridge 2 of the PA150 PCB boards. The function of DRV134 is to convert the un-balanced input signal to a balanced signal, so that the non-inverted signal is fed to one PA150, and the inverted signal is fed the another PA150. One of the PA150 is connected to the speaker’s positive input, and the other PA150 is connected to the speaker’s negative input. Because of this push-pull configuration, the total gain of the amplifier is doubled. Each PA150 has a gain of 20, so the gain of the BPA300 is 40.
300W 6x LM3886 Bridged Power Amplifier – [Link]
400W Stereo Audio Amplifier based on the original Marshall Leach involvement, but has made some improvements. Regarding the power supply voltage to the +-75V. VC comparing the performance of the modified Leach 700W/2R on one common board of both channels, as well as protection and control circuits for the fans. Compared to the 700W version a bit different in wiring. Because some things in the 700W version is completely tightened to perfection.
400W Stereo Marshall Leach Amplifier – [Link]
This audio power amplifier project is based on LM1875 amplifier module from National Semiconductor. It is able to deliver up to 30W of power using an 8 ohm load and dual 30V DC power supplies. It is designed to operate with minimum external components with current limit and thermal shutdown protection features . Other features include high gain, fast slew rate, wide power supply range, large output voltage swing and high current capability.
25W Audio Power Amplifier - [Link]