Audio Music

Audio Amplifiers, Preamps, MP3 Players, Musical Instruments.

This was a National Semiconductor Application Note, now TI. – Low Cost IC Stereo Receiver.

AN-147 Low Cost IC Stereo Receiver

Some Highlights

The LM3089 FM IF System does all the major functions necessary for FM processing, including a three stage amplifier/limiter and balanced product detector, as well as an audio preamplifier.

FM stereo demodulation is accomplished by the use of the LM1800 phase locked loop, thereby eliminating the need for external coils.

The AM function of the receiver is done completely with the LM3820 AM radio system. While designed for 3 section tuned superheterodyne application.

The LM382 dual preamplifier was selected for its minimum parts count and low noise capability.

Panel meters are employed in the FM system for both signal strength and center tuning, allowing for easy and accurate tuning. A directly driven LED offers immediate indication of FM stereo reception.

Low Cost AM FM Stereo Receiver

A single transistor tone control circuit was designed as the optimum cost/performance trade-off. The transistor is configured in a shunt-shunt feedback design, allowing gain variations between input functions.

The stereo power section, consisting of the LM378 dual audio amplifier, delivers 3W/channel with total harmonic distortion (THD) less than 1% and 4W/channel with THD less than 10%,

Amplimo has got a very large range of toroidal transformers available directly from stock. Standard range transformers have been approved by KEMA and UL . Built and tested according to the international standard EN61558 .

Amplimo – Toroidal Transformers

Sstandard range have a 230V primary and two equal secondary windings. These windings can be used individually or can be used in series or in parallel.

Amplimo - Toroidal Transformers

Standard range transformers are also available with 2x 115V primary to be used in series or in parallel.

Toroidal-Transformer.com – Here you can order Toroidal Transformers.

Amplimo presents a generation of amplifier modules offering outstanding advantages, allowing the rapid construction of quality audio amplifiers for many applications. These hybrid modules contain the complete audio amplifier circuit for connection between the preamplifier or mixer and loudspeaker, they are very stable even with complex loads and are therefore very reliable as the likelyhood of oscillation has been reduced to a minimum.

Amplimo BV
Industrieweg 14, NL7161BX, NEEDE, The Netherlands.

This site is offered in the hope that readers will better understand electric guitar technology, leading to creative use of your musical tools. Of course, only practice will improve your musical vocabulary and articulation….

GM Arts – Music Guitar Science

“Hello World! I live in Adelaide, South Australia, and my interests are electric guitar, playing live music, writing MIDI sequences, programming in Visual Basic, dabbling in electronics, with a casual interest in popular science. I have some years of experience in these fields, and use these Web pages to share my knowledge freely. ..”

GM Arts - Music Guitar Science

Electric Guitar

Most musical instruments and their amplification systems, such as those used for public address (PA), recording and hi-fi are designed to reproduce sound as accurately as possible. Electric guitar and its amplification is completely different: every item in the guitar signal chain is designed to modify the raw guitar signal in some way.

  • Guitar Amplifiers – valves vs transistors, some overdrive circuit ideas.
  • Guitar Pickups – get the most out of them alone and in combination,
  • MIDI Music – A guide on MIDI messages, circuit for a PC-MIDI interface.

Related Resources –

  • Pickup Winder Web Page
  • Overdrive schematics – partial designs
  • Pickup wiring and switching ideas

Here is a collection of web pages of VU Meter projects that helps a newbie getting into the Electronics DIY Hobby Land.

VU Meter Circuits and Projects

A Hobby now in your School days or College can help you build a strong profession later. It is Edutainment that will make productive use of your spare time. Friends can do it as a group, during holidays. Parents should encourage healthy hobbies, as the children will grow in a positive and creative atmosphere.

Stereo led level meter – This is it. It’s a STEREO LED LEVEL METER. It’s the cheapest and best bar graph display available and best of all, it uses readily available components.

VU-meter by Archy – Then it hit me. A VU meter, big, beautiful, professional! From that moment started my thoughts flowing. Those VU-meter ICs that are sold in every electronics shop?

LM3914 dot-bar display driver – The LM3914 is a monolithic integrated circuit that senses analog voltage levels and drives 10 LEDs, providing a linear analog display.

Knight Rider Display Project – This project started out as a VU meter. I reused parts and pieces to improve the VU meter and give it additional functionality. It is amazing how much time it takes to create a small thing like this.

40 Watts Hi-Fi Music System

Stereo Music player with Tuner, 1986, LED VU meter and Analog VU meter.

SAN 20

This was done as repairing home electronics was my hobby in school days, I learnt by building Amplifiers based only on transistors from the Old Philips Circuits and Books.

Home Made Circuits

The above one is TDA2020 20 Watts Per Channel, with LED input level meter and moving-coil output meters. It would have a 5 pin din input and RCA speaker output, input for phono, tape, etc. The Speakers had a woofer, tweeter and midrange with passive crossover network.

SAN 20 Speakers

Stereo Adapter for Portable Music Player

Low Cost Stereo Adapter 20 Watts for Portable Music Player 1984, Bass Treble and Presence.

Portable Music Player

This was a TB810 based 10+10 Watts Stereo Amplifier with LM381 or 2 Preamplifier, The portable player docks in a wooden cabinet. There was no IR, Wi-Fi or Bluetooth in those days, so the device would interface with amp thru a stereo ear-phone socket-jack system with a shielded cable. Bass, treble and Presence as per an old phillps audio amp book.

There is a very wide range of power amplifiers, preamps, guitar/ bass amplifiers, studio equipment, effects, and other projects to build, including loudspeakers, subwoofers, and many others

Elliott Sound Products – The Audio Pages

Elliott Sound Products - The Audio Pages

  • Projects – Complete listing of ESP’s free project and design articles
  • Articles – Informative articles about audio, building projects, and electronics in general
  • Buy PCBs for ESP Projects – boards supplied have very comprehensive documentation.

ESP Resource of Rod Elliott –  The above pages has many useful ideas and practical tips – delabs

It is by Hobby and DIY – Do it Yourself, Education Starts even without books. Then you need to read to enhance your abilities to Design your own.

In order to compensate or enhance your education, you need to work at a small shop as an apprentice even as a student, not for the sake of project work alone. An Evening job at a factory or a home mini workshop-lab is very essential for obtaining the skills – Solderman 1702

Dual Polarity Power Supply
Two versions of a dual polarity power supply with printed circuit board artwork. The supplies are built around the popular LM317 & 337 complementary voltage regulators which offer very high ripple rejection as well as short-circuit and thermal protection.

Jason Neals DIY Audio and Electronics

Microphone Preamplifier
A battery-powered microphone preamplifier and microphone wand for acoustic tests and recording. The preamplifier features 20dB of switchable gain and a clipping indicator,

Jason Neals DIY Audio and Electronics
An interesting website with many photos of electronic projects. There are not many projects but the description and photos and documentation are very useful for learning the art of circuit design.

Danish Audio ConnecT. High quality audio parts. High-End Audio Parts for Hi-Fi, A/V and Pro-Audio. DACT products are used by audio and A/V audio equipment manufacturers and by DIY audiophiles throughout the world.

Danish Audio ConnecT – Denmark

Back in 1995, the first DACT product was the well-know CT1 and later CT2 stepped attenuator, which still today remain the single most recognized state-of-the-art audio volume control.

Danish Audio ConnecT - Denmark

The CT100 is a two-channel phono preamplifier module with very accurate RIAA equalization and many features. It is realized with the best semiconductors available and non-inductive, low noise, SMD metal film resistors. The circuit is designed to accept both moving coil (MC) and moving magnet (MM) transducers/cartridges directly in order to eliminate the need for an external MC step-up transformer or amplifier. MC/MM input loading and input nominal level values are easy to select with high resolution by DIP-switches.

Danish Audio ConnecT A/S
Skannerupvej 14, DK-6980 Tim, Denmark.