Professional Stereo Encoder - Uses high quality NJM2035 stereo coder IC.
Pushpull Class a 2a3 Stereo Amp - The input stage is comprised of a both halves of a 6SL7 octal dual hi-mu triode in a differential amp configuration with a 1ma constant current cathode load. I'm using field-effect (constant-current) diodes for simplicity. the diff amp approach was chosen for good power supply rejection, ease of balancing, good gain, and ease of application of *feedback*, if desired (hey, i like to keep an open mind). It also takes care of phase-splitting right up front. Note: I've returned the constant current diode cathode to -9V instead of ground in order to avoid the non-linearities about the pinch-off region (Vpo ~= 1.5V) __ Designed by Bob. D. @ robert.m.danielak @ lmco.com
Quadraphonic Amplifier - This is a four channel amplifier ideally suited for use with quadraphonic equipment such as a Sound Blaster Live card. There is no volume control, audio levels being directly controlled from the sound card itself. __ Designed by Andy Collison
Ramsey 25 BA1404 Stereo FM Transmitter - Stereo FM transmitter based on BA1404 and 145170 frequency synthesizer IC.
RIAA Corrector - To listen old vinyl LP's in a correct sounding on a sassy with dynamic cartridge you need a circuit, named RIAA corrector. This circuit you can find in old amps, but it isn't embedded in home cinema equipments or amplifiers __ Designed by Gabor Toth
RIAA Equalized Stereo Phono Preamp - This riaa Pre-Amp is the perfect solution to getting a signal off of your old turntable and into your mixing board. Whether you want to grab a couple of loops from a 70’s LP record or just archive your record collection you need an riaa compensated pre-amp to do it. __ Designed by John Simonton
Signature Series Kit Loudspeaker SystE - M - These new speakers are among the very best kit speakers that money can buy. They use the very-high-performance Fountek ribbon tweeters and Peerless woofers. They will be a very good match to our recently described 20W Class-A Stereo Amplifier. __ SiliconChip
Simple Circuit FM Stereo Transmitter - (ATTINY12, ATTINY25, ATtiny2313, AT90S2313, AT90S232, or nearly any other CMOS
microntroller-Yes probably even a PIC!) This project appeared in the December, 2007 issue ofInfo Elektronika Magazine __ Designed by © Richard Cappels
Simple Circuit Surround Sound Decoder - This surround-sound decoder is based on the "Hafler" principle, first discovered by David Hafler sometime in the early 1970s. The original idea was to connect a pair of speakers as shown in Figure 1, for use as the rear speakers in the surround setup __ Designed by Rod Elliott ESP
Simple Circuit Surround Processor - Simple Surround Processor. This is built with only conventional parts, and digital delay block, too. So it is very easy to build. __ Designed by The Electronic Lives Manufacturing-presented Chan
Simple Circuit Stereo Electret Microphone PreAmplifier - The leftmost 10k resistor supplies plug-in-power to the electret, forming part of the FET amplifier in the electret capsule. This could be anything from 2k to 10k, the higher the better the stereo separation (another mic derives bias from the same rail). Apparently higher values also lower distortion, and the best bias power circuits involve actually breaking a trace on the electret capsule to allow the use of both a drain & source resistor, but I’m not going that far.
Simple Circuit Two-Line Output Combiner - Sometimes there is need to combine the output of two line level audio sources to be fed to one input. A standard way in professional audio is to use a mixing desk, but on home audio system you might want to look for a simpler and less expensive alternative. Some people have suggested of combining two audio outputs with an "Y-adapter" which is ment to split one output. Those adapters are just one male connector and two feamle connector directly wired to each other in the followin way: __ Designed by Tomi Engdahl
Simple Stereo VU Meter - I like to see lights move to music. This project will indicate the volume level of the audio going to your speakers by lighting up LEDS. The LEDS can be any color so mix them up and really make it look good. The input of the circuit is connected to the speaker output of your
Spatial Distortion Reduction Headphone Amp - The schematic in Figure IV is a prototype circuit that implements the required frequency and crossfeed contouring. As a development objective, the low and high frequency contouring and crossfed control elements must not interact-they must be independently adjustable __ Designed by © John Conover
Single Ended Class A2 SV811 10 Stereo Amp - This project actually began its life as a Single-ended 211 design. I received the Parts Connection Catalog just before Christmas (1995). In the back were the data sheets for various tubes, including the lovely 211. I had been hearing a lot of good things about this tube, so I started pokeing around. Most designs I found used a B+ between 850 and 1200VDC. While I wasn't _too_ put off by these relatively high voltages, I wondered if I couldn't just come up with something a little more manageable. Around the same time I began top hear a lot of noise about Class A2 designs using 801's or 805's, etc. Hmmmm __ Designed by robert.m.danielak
Stereo Audio Compressor - Do you hate the way the sound level on your TV suddenly jumps during the advert breaks? Or do you find that the sound levels vary widely when switching between digital TV stations? Or maybe you have problems listening to CDs or MP3s in your car or against the background din during a party? Are the soft parts too soft and the loud parts too loud? This Stereo Compressor will solve that problem. It reduces the dynamic range of the signal while still maintaining clean sound. The unit is also ideal for use with PA systems. __ SiliconChip
Stereo Audio Isolator - This circuit is useful for removing ground loop hum on a remote line level audio signal line. It can be used to to connect a computer sound card to a stereo amplifier's line input. Other uses include tapping into a line level signal for powering a remote amplifier, and removing common mode ground interference on 12 Volt audio equipment such as a car stereo. The circuit can be used in mono applications by simply ignoring the second channel __ Designed by G. Forrest Cook
Stereo brick Amplifier - This is a circuit for a stereo brick amplifier that can be used as an enhancement to low-cost DVD players to play the effects of Dolby digital DVDs. __ Designed by Raj K. Gorkhali
Stereo Broadcast Limiter - Circuit for the Ramsey FM10a/FM25 Transmitter __ Designed by G. Forrest Cook
Stereo Channel Selector - The add-on circuit presented here is useful for stereo systems. This circuit has provision for connecting stereo outputs from four different sources/channels as inputs and only one of them is selected/connected to the output at any one time. When power supply is turned ‘on’, channel A (AR and AL) is selected. If no audio is present in channel A, __ Designed by G. Forrest Cook
Stereo Coder Multiplexer - With BA1404 and 15 KHz low pass filters.
Stereo Electret Microphone PreAmplifier - The leftmost 10k resistor supplies plug-in-power to the electret, forming part of the FET amplifier in the electret capsule. This could be anything from 2k to 10k, the higher the better the stereo separation (another mic derives bias from the same rail). Apparently higher values also lower distortion, and the best bias power circuits involve actually breaking a trace on the electret capsule to allow the use of both a drain & source resistor, but I’m not going that far.
Stereo FM Transmitter - This is a small stereo FM transmitter. Output can be tuned from 88 to 108Mhz and the transmitter can be battery powered or be used with presented low voltage power supply. This circuit is based on the Rhom BA1404 datasheet. The maximum voltage should not exceed 3V. The IC can be driven from a 7805 Regulator with a couple of 1N4001 diodes to reduce the supply voltage to about 2.8 Volts. RF output power is typically 500mW but range depends upon antenna coupling and efficiency, environment and size of antenna. A small telescopic whip has an expected range of at leaset 100 metres or more.
Stereo FM Transmitter with BA1404 - With this Stereo FM Transmitter with BA1404 you will be able to create a mini stereo FM station and broadcast to your entire home, a simple way to have an audio link wireless with ease. With the FM transmitter BA1404 Hifi Stereo you can stream your music from your iPod MP3, satellite receiver, computer, DVD player, Mobile Phone, MP4 player and MP3 and other audio source directly to an FM receiver with crystal clear sound.
Stereo Headphone Amplifier - This is an improved version of headphone amplifier I've built many years ago. I wanted so much to share it with you because this simple circuit has done a great service
Stereo jack adds no-cost power/logic control - EDN-Design Ideas – April 15, 1999 [ NOTE
: File has multiple design, scroll for this one.] Many battery-powered devices use peripherals that require only two conductors to complete their interfaces. You can use stereo phone jacks and monaural plugs to perform power- or logic-control functions in addition to completing their required I/O connections. Monaural plugs short-circuit the ring and sleeve of stereo jacks. You can place the ring connector, normally considered a redundant ground return, into service as an spst switch. __ Circuit Design by Gary O’Neil, IBM Microelectronics, Research Triangle Park, NC
Stereo Line Driver - A stereo line driver for feeding long cables or buffering an audio source. __ Designed by Andy Collison
Stereo PreAmplifier - Simple circuitry suitable for moving-magnet cartridges. Passive high-frequency equalization __ Contact: Flavio Dellepiane, fladello @ tin.it
Stereo Synthesizer - Different frequency ranges appear at the two outputs, depending on the setting of the controls and create a stereo effect __ Designed by Ethan Winer
Stereo Test Tone Generator - This circuit produces two audio frequency sine waves with different frequencies but equal amplitudes. It can be used for testing a variety of stereo audio equipment. The circuit was originally developed the purpose of aligning an FM Stereo Modulator, like the type used in low power FM stereo transmitters. Two tone outputs are available, the low tone has a secondary output that is 180 degrees out of phase with the primary output. The circuit is also handy for testing computer sound card inputs. A variety of waveform configurations can be produced by plugging a stereo audio patch cord into the four output jacks. __ Designed by G. Forrest Cook
Stereo Tube Amplifier - The circuit is simple, yet is capable of excellent performance. I designed it specifically for use as an amplifier for the digital sound card in my computer. Audio input can be from any two-channel line level device such as a television, CD player __ Designed by Aaron Cake
Stereo Width Controllers - Sometimes, for a variety of reasons, it would be nice to vary the width of the 'sound stage' when listening to stereo recordings. Although technically this is anything but hi-fi, it is a useful addition to PC speakers, or even for the music centre in the listening room. __ Designed by Rod Elliott ESP
Stereo-amplifier IC's outputs drive multiple loads - 11/21/05 EDN-Design Ideas Reference provIdeas constant bias voltage regardless of supply-voltage variations__ Circuit Design by Jean-Jacques Avenel, Maxim Integrated Products, Lesigny, France
Studio Series Stereo Headphone Amplifier - A top-class unit for the audio enthusiast! __ SiliconChip
Studio Series Stereo Preamplifier - Designed for the audio perfectionist, this superb preamplifier uses the latest high-performanceop amps for ultra-low noise and distortion __ SiliconChip
Studio Series Stereo Preamplifier - Installing The Modules In A Case __ SiliconChip
Surround Effect - First, check out your existing stereo system to see if it already accommodates surround sound. Many systems, even some low cost mini units, already have connections for matrix surround. If you see an additional pair of speaker jacks (usually labelled "rear") in the back of the unit, then you most likely have surround sound capabilities built-in to your current gear. Many such systems also have a switch labelled "two-by-two matrix" or "matrix surround". This has to be switched on, after the additional speakers have been attached, to activate the matrix circuit. __ Designed by Chris Kantack
Surround Sound Decoder - This surround-sound decoder is based on the "Hafler" principle, first discovered by David Hafler sometime in the early 1970s. The original idea was to connect a pair of speakers as shown in Figure 1, for use as the rear speakers in the surround setup __ Designed by Rod Elliott ESP
Surround Processor - Simple Surround Processor. This is built with only conventional parts, and digital delay block, too. So it is very easy to build. __ Designed by The Electronic Lives Manufacturing-presented Chan