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Phono Preamplifier: (electronic schematic /
circuit added 2/05) |
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Portable Headphone Amplifier: (circuit added 9/04) |
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Portable Headphone Amplifier: (electronic
schematic / circuit added 2/05) |
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Portable Microphone PreAmplifier: High headroom input
circuitry. 9V Battery powered. (added 9/04) |
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Portable Mixer: (electronic schematic / circuit
added 2/05) |
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Push-Pull Class a 2A3 Stereo Amp Valve:
(electronic circuit added 1/03) |
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Push-Pull Class a Amp using Type 5687 Dual Triodes:
(electronic circuit added 1/03) |
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Quadraphonic Amplifier: This is a four
channel amplifier ideally suited for use with quadraphonic equipment such as a Sound Blaster Live card. (added 5/02) |
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Radio Shack Pressure Zone Microphone PZM Modifications:
(electronic schematic added 8/02) |
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Rane MS 1B Microphone PreAmplifier Circuit Diagram: This is a
circuit diagram of a commercial high quality balanced microph1-preamplifier. This document is in PDF format. (added 4/02) |
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Regenerative Audio Amp: This circuit provides
extremely high open-loop gain. Stable controlled gain of 100+ is easily possible. (added 09/05) |
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S/PDIF Digital-to-Analogue Converter: (electronic circuit
added 10/05) |
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Settling Time of Operational
Amplifiers: AN-359 Analog Devices Application Notes (app note added 2/06) |
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SIM - The Simple Version: The smallest variation in
amplifier performance is shown with this simple circuit (circuit added 6/07) |
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Simple AV Audio/Video Wireless Transmitter: (electronic Circuit added
7/06) |
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Simple High Quality Hi-Fi Preamp: As it says - simple,
high quality preamp. Has all the facilities normally expected (added 5/07) |
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Simple Surround Processor: Simple Surround Processor.
This is built with only conventional parts, and digital delay block, too. So it is very easy to build. (added 10/05) |
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Single Chip 50 Watt/8 Ohm Power Amplifier sound.ad: Uses LM3876 Hi-Fi
amplifier IC from National Semiconductor (added 6/03) |
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Single Chip 50 Watt/8 Ohm Power Amplifier: Uses National
Semiconductor LM3876 Power IC. Voltage gain is 27dB. Voltage gain is 27dB as shown, but this can be changed by using a different value resistor for the feedback path (R3, currently 22k,
between pins 3 and 9). The inductor consists of 10 turns of 0.4mm enameled copper wire, wound around the body of the 10 Ohm resistor. The insulation must be scraped off each end and the wire
is soldered to the ends of the resistor. (added 10/05) |
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Single Ended Class A2 SV811 10 Stereo Amp:
(electronic circuit added 1/03) |
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Small Amplifier Circuit: Uses many amplifier ICs,
from few-Watts to200-Watt (added 4/02) |
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Soft Start Circuit for Power Amps: Designed for (large) toroidal
transformers, limit the inrush current to a sensible value. (diagram added 6/03) |
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Sony C 37Condenser Microphone: information with
circuit diagram (added 5/02) |
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Sound Controlled Flip Flop:
Described here is a very inexpensive solution to many phono-controlled applications like remote switching on, for instance, or activating a camera, tape recorder, burglar alarms, toys, etc.
The circuit given here employs a condenser microphone as the pick-up. A two-stage amplifier built around a quad op-amp IC LM324 offers a good gain to enable sound pick-up upto four metres.
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(added 10/05) |
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Spatial Distortion Reduction Headphone Amp: (diagram
added 6/03) |
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Speaker signals to line level inputs : The circuit is
designed to work with typical HIFI amplifiers where negative speaker connector (black) is connected to amplifier ground. Be careful here because some modern amps have both terminals actively
driven. Connecting either one to a common reference could cause the output stage to smoke.... (added 11/05) |
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SPICE Protection: National Semiconductor Application Note
(app note added 2/06) |
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Stereo Audio Isolator: (electronic schematic /
circuit added 2/05) |
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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.... (added 10/05) |
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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,
(added 10/05) |
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Stereo Headphone Amplifier: Simple three transistor amplifier
Class AB. (circuit added 8/06) |
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Stereo Mixer: (electronic schematic / circuit
added 2/05) |
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Sub Woofer Processor: Designed to operate a sub-woofer
driver below its resonant frequency. (schematic added 6/07) |
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Subwoofer Equaliser: The Linkwitz transform circuit is a hugely
flexible way to equalize the bottom end of a sealed loudspeaker enclosure. A speaker that is corrected using this method is flat from below resonance to the upper limit of the selected driver.
The low frequency roll off point is determined by the parameters of the transform circuit. Should the enclosure size be too small and cause a lump in the response before roll off, this is also
corrected. A conventional active crossover network is then used to divide the subwoofer signal from the main channel signals. Note that there is also a separate spreadsheet calculator
available for calculating component values for different situations not handled by the original circuit. (added 7/03) |
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Subwoofer Equaliser: This is a constant Q design, eight 1/3 octave
bands covering 20Hz to 100Hz.(electronic circuit added 7/03) |
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Subwoofer Phase Control: A standard phase control for
use with subwoofers. (schematic added 6/07) |
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Super Capacitor Powers Audio Amp: 03/14/96
EDN-Design Ideas / (added 3/03) -Micro power and low-voltage op amps allow you to build high-performance analog-signal processors that require no batteries or wall transformers,
this simple mixer is powered using one large capacitor such as a Supercap or Dynacap for some Time |
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Surround Processor: Simple Surround Processor. This
is built with only conventional parts, and digital delay block, too. So it is very easy to build. (added 10/05) |
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Switch-mode Power Supply for a Tube Car Amplifier:
(electronic design added 6/07) |
