This is a PDF in English published in 1947 and features 45 complete schemes of tube amps, including diagram drawing material list and description of operation. Ideal for anyone interested in old amplifiers (Vintage) and the supporters as well as a modern valve amplifier. The power of the circuits presented in the book ranges from 1 to 75 Watts.
Practical Amplifier Diagrams – Tubes Audio Power Amplifiers - [Link]
Company Hammond Manufacturing is probably familiar to you in context with high quality aluminium and plastic enclosures. But Hammond Manufacturing also produces a wide range of audio transformers, chokes and lamp transformers.
Audio transformers are mainly known to those, who work with professional sound equipment, microphones and high-end lamp amplifiers. A main function of transformers in audio devices is above all impedance matching. Various audio signal sources, like for example microphones, have an impedance different from impedance required for further signal transmission. Naturally, without impedance conversion, a direct connection into a transmission chain would cause a significant change of signal level, moreover frequency dependent, lower resistance to interference, or an overload of an end stage (at a lamp amplifier). At the same time transformers provide a galvanic disjunction, thus their usage is often convenient also from safety reasons.
Advantages / Features:
- top quality
- balanced frequency response
- low insertion loss
Hammond Manufacturing has long-term experience with a development and production of audio transformers. In a production portfolio we can find various series, from simple ones up to top wideband series, like for example the 850A series with a frequency response +/- 0.5 dB from 20 Hz to 20 KHz. Another group of components consist of lamp transformers. Here we can find output transformers, supply transformers, chokes, but even drivers and also many construction components.
Top quality Hammond audio transformers - [Link]
Hack a Week’s new project this week is a single NPN transistor audio preamp – [via]
Here’s a great little project that goes well with the LM386 audio amp. It’s a good first time transistor project because it’s simple and demonstrates the common emitter class A amplifier circuit with only six components in the signal path.
The single NPN transistor audio preamp - [Link]
On my desktop PC I have a speakers and a headphones. Usually I use headphones, but when I need to switch to speakers I need to physically plug in speakers instead of headphones to my PC’s soundcard. I wanted to solve this problem for a long time, but never get around of that until recently I saw this posted on Hackaday.
And so I’ve decided to build my own really simple audio multiplexer.
USB Audio Multiplexer - [Link]
Atmel launches digital audio development system – [via]
Atmel Corporation has announced a complete hardware and firmware digital audio solution aimed at simplifying the design of digital audio equipment for consumer, automotive and industrial applications. Based on the Atmel’s AVR UC3 microcontrollers, the Digital Audio Platform is specifically tailored for audio applications such as USB docking stations for smartphones and media players.
The platform comprises dedicated microcontrollers, evaluation kits and firmware IP. The firmware IP includes control and streaming interfaces for popular smartphones and portable media players as well as MP3, WMA and AAC decoders, USB protocol stacks, and a complete file system to allow designers to utilize mass storage devices such as USB flash disks and SD cards. The Digital Audio Platform is ideal for applications including docking stations, USB mass storage, SD card playback, car stereos, USB speakers, microphones, and various voice and music equipment.
Atmel launches digital audio development system - [Link]
I built my first power amplifier when I was still in secondary school. The circuit was made of transistors, didn’t provide much power and had an ugly PCB.
Around the same time I got access to a datasheet of TDA1524, a tone/volume control circuit, and I decided to use it to build a pre-amplifier, to improve the quality of the sound coming out of the amplifer. Both circuits worked well for almost a decade but the old amplifier was never up to my expectations.
In 2006 I decided that it was time to build a real power amplifier, this time based on an integrated circuit to reduce the number of external components and cost.
Stereo Audio Amplifier with a TDA2616 - [Link]
Signal Wizard 3.0 is a very powerful audio signal processor that features multichannel synchronous processing. It can mix, amplify, filter, delay and adjust the phase of individual input signals, selected by using the included intuitive PC software. Signal Wizard 3.0 features a 24-bit, 96 kHz codec with six analog input and eight analog output channels, and an internal DSP processing speed of 0.6 GMACs. Signal Wizard 3.0 also incorporates two digital audio (S/PDIF) inputs and outputs. Like its two channel equivalent Signal Wizard 2.5, the software requires no knowledge of mathematics or programming.
Signal Wizard 3.0 includes very powerful mixer functions – any channel can be blended with any or all of the other channels in any proportion, since the system incorporates mixer units at the input and output signal stages. Signal Wizard 3.0ʼs unique filter design engine enables standard filter types to be created using the easy-to-use graphical software, but it also allows completely arbitrary frequency responses, both in amplitude and phase, to be realized via a simple text file import. Read the rest of this entry »
400W car power amplifier. Based on a push-pull converter with TL494 (KA7500) driver, 500W of power is enough for four TDA7294 integrated amplifiers. Three three-digit multimeters on front-panel shows actual battery voltage, temperature, and estimated output power.
4x100W car audio amplifier – [Link]