Tag Archives: Audio

GPiO Audio Measurement Toolbox

tool-box-1

by Sagar Savant:

Measuring performance of audio components like microphones, speakers, converters, and amplifiers can be a difficult task. In this post, I’ll talk about some of the tools I use to make this job easier. Analyzers, reference transducers, calibrators, meters, and more come with various feature sets and price tags. The items below just happen to be my favorites.

Soundcheck (Listen Inc.): Soundcheck is a versatile audio analyzer that I’ve used for years in both R&D and production line environments. It’s built in a “modular” way, so you buy the features that you need. What I love about this software is the customization potential in everything from the granularity of frequency points in a sine sweep to the ability to post process measurements in a sequence automatically based on macros. Soundcheck is not cheap, but it saves me tons of time when I need to measure and report on audio components or subsystems.

GPiO Audio Measurement Toolbox – [Link]

6EM7 Single-Ended Triode (SET) Vertical Amplifier

DIY-6EM7-SET-Vertical-Amplifier

by Matt Renaud:

What really drove me to build this 6EM7 amp was an idea about amplifier layout. Looking back at most of my tube designs, and most of those on the internet, revealed a very typical pattern. Amplifiers tended to be flat chassis with tubes and transformers above and electronics below. From a historical perspective this makes perfect sense. Metal chassis were built this way to facilitate packaging and assembly. When people started to make tube amplifiers again, they just removed the upper case and built in the same way.

6EM7 Single-Ended Triode (SET) Vertical Amplifier – [Link]

Tiny audio amp produces 1.9 W from 5 V

20150528025534_pam8905-3

by elektormagazine.com:

The PAM8905 is a new audio amp chip from Diodes Incorporated measuring just 1.5 x 2.0 mm. The design operates in class D mode, achieving a total harmonic distortion of 1% (plus noise) and delivering a maximum of 1.9 W into 8 ohm using a power supply in the range between 2.8 V to 5.2 V. The PAM8905 features an integrated boost converter powering the output stage to achieve the rated output power and maintaining volume with falling battery voltage. The boost converter is a fully synchronous design, ensuring a low external component count and high efficiency.

Tiny audio amp produces 1.9 W from 5 V – [Link]

3D Spectrum Analyser

by Dooievriend @ tweakblog.tweakblogs.net:

More than a year ago, a friend of mine asked me to write the software for his 3D Spectrum Analyser (3DSA): a device that takes as input an audio signal, and outputs its visualisation on a 3D matrix of leds. If the above description doesn’t quite ring a bell, simply watch the end result in action.

First things first though, the microprocessor to be programmed was an 80MHz Olimex PIC32, soldered to the PIC32-PINGUINO-OTG development board. (For those who ever tinkered with Arduino boards: it’s the same, only with a faster chip and fewer builtin libraries ) The Algorithm had to sample the input signal at regular time intervals, convert this signal to the frequency domain, and visualize the detected frequencies on a 16x16x5 LED matrix.

3D Spectrum Analyser – [Link]

Mini Stereo Audio Amplifier

Mini_Stereo_Audio_Amplifier

The dual low power amplifier built around TDA2822 8pin DIP. IC, it is mainly designed to use in portable players, radios and other building block project. A 3V supply can be used to drive headphones providing 20mW in 32 Ohms per channel, and a 12V power supply will provide 1W in 8 Ohm per channel for small loudspeakers.

Mini Stereo Audio Amplifier – [Link]

10W Stereo Audio Amplifier

10W_Stereo_Amplifier_PIC

The project built around Philips TDA1521 IC, The project provides high quality audio 2X10W Audio output. The device is especially designed for mains fed applications, (e.g. Stereo TV Sound and Stereo Radio). The circuit designed for asymmetrical power supply systems.

10W Stereo Audio Amplifier – [Link]

5.5W – 2 Channel Audio Amplifier

5.5W_2_Channel_Audio_Amplifier

This is a small 2 Channel amplifier constructed around Sanyo’s LA4445 IC delivers 5.5Watts +5.5 Watts at 4 ohm load, supply in 12V DC 2Amp, Input impedance 30K.

Specifications

Dual Channels output : 5.5W
Minimum External Parts
Very small pop noise at the time of power supply ON/OFF
Good ripple rejections
Small residual noise
Built-in protectors 1. Thermal Protector 2. Overvoltage Surge Protector
Standard Audio signal
Supply 12V DC
Load : 4 Ohms Speaker on Each Channel
Voltage Gain : 50DB
Output 5.5W on each Channel (THD 10%)
Total harmonic distortion 1% Max @ Po=1W
Input impedance 30 K-ohms

5.5W – 2 Channel Audio Amplifier – [Link]

20W Bridge Audio Amplifier

20W_BRIDGE_AUDIO_AMP

20W Bridge Audio Amplifier project, based on the TDA2005 IC, The TDA 2005 IC is class B dual audio amplifier, specifically designed for car radio applications etc.

Specifications:

Power supply input : 18 VDC
Output power : 20 W, 4 Ω
IC built in Thermal Shut-down, Load dump voltage surge protected
Terminal pins for connecting left and right audio signal inputs
Berg Connector for connecting Potentiometer (POT) for volume adjustment
Power Battery Terminal (PBT) for easy power supply and speaker connection
Power-On LED indicator
Heatsink for IC
Four mounting holes of 3.2 mm each with nut and stud
PCB dimensions 63 mm x 65 mm
Note : Use shielded cable for connecting potentiometer

20W Bridge Audio Amplifier – [Link]

14W Stereo Audio Amplifier

14W_STEREO_AUDIO_AMP

14W Stereo audio power amplifier build around LM4730 IC. The LM4730 is stereo audio amplifier capable of delivering typical 14W per channel of continues average output power a 4 Ohms or 8 Ohms load with less than 10% THD+N from 20Hz to 20Khz frequency. Each amplifier has an independent smooth transition fade-in/out mute and a power conserving standby mode which can be controlled by onboard slide switches.

The LM4730 has short circuit protection and thermal shutdown feature that is activated when the IC temperature exceeds 150 centigrade. The LM4730 also has under voltage lock out feature for click and pop free power off and on. Amplifier required proper heat sink.

14W Stereo Audio Amplifier – [Link]