Electronics-Lab.com Blog

Sebastian built an experimental record/looper circuit, resulting in some interesting sample contortionism. [via]

This circuit currently has a few ways to manipulate audio. These are:

A record button allows the user to sample incoming audio to a RAM buffer

A potentiometer sets the input level

A potentiometer sets the sample rate / pitch for playback. The changing of sample rate can be recorded if desired, by physically changing the position of the pot during recording.

The address lines A0 – A18 can be manipulated ie. moved around, removed, replaced, giving a wide range of effects such as stuttering, repeating and basic granulation.
Although this does not sound like heaps of manipulation, keep in mind that this circuit can absolutely mangle a sound beyond recognition. The ADC is running at its maximum speed, and as such the sample rate can be varied greatly for example.

Audio looping & manipulation in RAM - [Link]

Audium Semiconductor has launched an audio power amplifier IC which, at normal listening levels, is 20 times more efficient than competing devices, such as Class D amplifiers, without compromising audio quality. The AS1001 operates from a nominal 1.5 V power supply and delivers 100 W peak power output. The amplifier is so efficient that battery-powered amplified loudspeakers can run for up to 10 months on a set of four ‘C’ batteries, playing for three hours per day.

AS1001 chip outputs 100 watts of audio from 1.5 volts - [Link]

I want to build high quality preamplifier with built-in DAC from SPDIF or USB for my power amplifier Leachamp. I had available circuit PCM2902. I tried to design DAC from USB with this circuit on one-sided PCB and I was succesful.

USB audio DAC - [Link]

Mark Houston writes:

The very first pair of speakers I put together some thirty-eight years ago was a pair of single-driver loudspeakers using 8” Kaltro twin cone drivers. As I type this, I find myself once again listening to speakers using a single full-range driver. This time it is the 6.5” Fostex FE167E fullrange driver. I had recently completed a small low wattage 6T9 valve amplifier, and asked Gio for some suggestions on speakers to match the amp. He suggested the Fostex FE167E. When I saw they were 94dB efficient I ordered them instantly. Packaged with the drivers were two enclosure plans – a floor-standing unit as well as a bookshelf enclosure. I opted for the smaller bookshelf speaker box. The Fostex Recommended Standard Bass Reflex Type Enclosure is 15L with a 50 by 50 mm port that can exit from the front or rear.

Fostex FE167E Bass Reflex Speakers – [Link]

This complete high quality, low noise mono audio power amplifier is based around the Hybrid Integrated Circuit STK4050 manufactured by Sanyo. The circuit incorporates volume and has a maximum music output power of 200W.The circuit incorporates an on board power supply; therefore, only centre tapped transformer is required to power the circuit. I t has very good quality sound. U can use it with your Home Theatre your PC & etc… You can also use it as Subwoofer Amplifier. It is a compact package for THIN-TYPE Audio sets. Easy Heatsink design to disperse heat generated in THIN-TYPE audio sets. Constant-Current circuit to Reduce supply switch-ON and switch-OFF shock noise. External supply switch-On and switch-OFF shock noise muting, Load short-circuit protection, thermal shutdown and other circuits can be tailored-designed.

200W Audio Amplifier – [Link]

Above schematic is for a three channel audio mixer. That will provide an overall gain of one between the output and each input channel. Each input channel includes a single 0.1uf capacitor and 100-Kilohms resistor to provide an output impedance of 100K. The number of input channels to this audio mixer can be increased by adding more capacitors and resistors with same value as capacitor(0.1uf) and resistor(100K). The mixer should be located between the output of tone control circuitry and the input to the power amplifier. One input should be taken from the output of the tone control circuit, and the other inputs should either be grounded or taken from desired source.

Three Channel Audio Mixer - [Link]

I want to build high quality preamplifier with built-in DAC from SPDIF or USB for my power amplifier Leachamp. I tried to design DAC from USB with this circuit on one-sided PCB and I was successful.

Schematics is from datasheet of PCM2902. Circuit includes DAC and ADC, SPDIF output and input and HID part with 3 buttons for MUTE, VOL+ and VOL-. I used only DAC part. Other parts are not used. For high quality playback is needed to use external low-drop voltage stabiliser for DAC part. I used LP2951CM which was available at local store. Output voltage is set to about 3.7V with two resistors. Circuit board is designed regarding to good ground placement and separating of analog and digital ground. These ground are connected in one point at USB connector. [via]

USB Audio Digital to Analog Converter - [Link]

This project used for detecting any audio signal with justable noise offset. It could be used to generate a radio mute signal eg. from a PDA.The circuit is consisting of:Input impedance ,Signal amplifier, Rectifier , Justable comparator (Noise offset). [via]

Audio Detector - [Link]

diyAudioProjects.com has a great collection of DIY audio Projects. DIY Audio Projects documents several DIY HiFi audio projects for Audiophiles. Projects include vacuum tube amplifiers, gainclones (chip amps), mosfet amps, preamplifiers, loudspeakers and cables. Visit the link below to check it yourself. Sure you will be amazed!

DIY Audio Projects - [Link]

Wouldnt it be sweet if you could have your micro play-back complex things, over audio for an extremely low cost? Imagine replacing that one i/o line that used to drive an led, be able to reproduce the human voice and exclaim “Hello world”, This can be useful in projects where you would like to add some human interface, but an lcd would be too bulky / to slow.

PWM audio generation with an AVR - [Link]