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20 Watt Power Amplifier - The LM1875 is a monolithic power amplifier offering very
low distortion and high quality performance for consumer audio applications...(added
04/2002) |
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20 Watt Stereo Amplifier (Randy Linscott) - This circuit is very basic to build
and puts out great power for your car or home. Keep all leads as short as
possible….(added 08/08/08) |
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20 Watt/ Channel Stereo Power Amplifier - Based on the versatile LM1875 from
National Semiconductor (added 6/07) |
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200 Watt Amplifier - (electronic schematic / circuit added 4/02) |
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200W MOSFET Amplifier - A compact audio powerhouse ideal for guitar or PA work or
for use as a general-purpose subwoofer or hifi amplifier. Many people prefer Mosfets
because of their legendary ruggedness. Altronics had a Mosfet amplifier module which
produced 200W…(circuit added 04/08) |
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20W Bridge Audio Amplifier - 20W Bridge Audio Amplifier kit, based on the TDA2005
IC, a class B dual audio amplifier, specifically designed for car radio applications
etc..(design added 08/08) |
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20W T-AMP - This amplifier is a standard datasheet aplication of Tripath
TA-2020-020 T-class IC. It offers 20W on 4ohm load with efficienty of up to 88%. The
whole amplifier was bought as a AMP6 kit from 41hz.com. The PCB board looks really
good and the copper on both sides is quite thick. The kit contains only high quality
components such as 1% metal film resistors or Panasonic FC input capacitors. Because
of such high efficienty the chip doesn't really require a heatsink. I used such a big
one only because I had it. Before starting soldering please read the Assemble Manual
so that even beginers will cope with building this amplifier. For more information you
can visit the AMP 6 forum. ….(electronic schematic added 11/08) |
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21W Class AB Amplifier - This is an instrument amplifier for monitoring music when
on stage. It provides 21W output power of this little design. Previously I had a
decent 10W amplifier (RED Free Circuits), but we blew that one somehow. Now I will put
this into the old box. I haven't built it yet, but the simulations say it works as I
designed. In this design, wiring is important due to no differential amplifier. I
might need to add ripple rejection with a zener as in the above design. ….(circuit
design added 11/08) |
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22 Watt Stereo Amplifier - The 22 watt amp is easy to build, and very inexpensive.
The circuit can be used as a booster in a car audio system, an amp for satellite
speakers in a surround sound or home theater system, or as an amp for computer
speakers. The circuit is quite compact and uses only about 60 watts.….(electronic
schematic added 03/08) |
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22W Audio Amplifier - The 22 watt amp is easy to build, and very inexpensive. The
circuit can be used as a booster in a car audio system, an amp for satellite speakers
in a surround sound or home theater system, or as an amp for computer speakers. The
circuit is quite compact and uses only about 60 watts....(circuit added 09/08) |
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24 Watt Class A Amplifier - A 24 Watt Class A Amplifier made from discrete
semiconductors, built and tested by Marc Klynhans from South Africa.…(circuit added
04/08) |
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25 W Class A Amplifier - Musical Fidelity would let you believe that this is a
Class A design. However, in common with most commercial amplifiers, it is a class AB
amplifier, it simply has a rather high standing current in the output stage, which
results in the first 8 watts or so being class A. ….(circuit design added 11/08) |
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25W Mosfet audio Amplifier - ….(circuit design added 08/08) |
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2-Input Mixer - As simple as it gets. mixer consists of two transistor-based
preAmplifiers. first one (designated "Mike in") offers higher gain. it works well
with a regular dynamic microphone. second one can be used to control audio input from
a tape recorder/CD player. (added 10/05) |
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2N2222 40 Meter CW/DSB Tranceiver - In spring of 1998, NorCal sponsored a contest
to design and build a project using no ICs and 22 or fewer 2N2222s as the active
semiconductor devices. I thought this was a really intriguing idea, so I set about to
design my version.....(electronic Circuit added 7/06) |
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2N3055 Power Amplifier - In spring of 1998, NorCal sponsored a contest to design
and build a project using no ICs and 22 or fewer 2N2222s as the active semiconductor
devices. I thought this was a really intriguing idea, so I set about to design my
version. ….(circuit design added 08/08) |
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2-Step Power Conversion: Portable Power for the Future - Design Solutions 8
Design Notes (Linear Technology) (app note added 73/06) |
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2-Transistor Amplifier - A simple two-stage amplifier. Use any general-purpose NPN
with high gain. It will drive low impedance headphones directly. A speaker will
probably require further boost…(added 05/05/05) |
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2W Amplifier - Amplifier operates in Class AB mode; single 470R preset resistor
controls quiescent current flowing through BD139/140 complimentary output
transistors. Adjustment here, is a trade-off between low distortion and low quiescent
current. Typically, under quiescent conditions, ... (added 4/05) |
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2x30W (stereo) Amplifier with STK465 - A amplifier of acoustic frequencies can be
manufactured with discernible materials, despite is known so much the difficulties of
finding of materials, what the problem of regulations. These difficulties are overcome
relatively easily if we find amplifier in form completed….(design added 08/08) |
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3 Channel Spectrum Analyzer - This 3 channel 15 LED spectrum analyzer is the
perfect addition to any audio amp project. It produces fantastic displays on three LED
bars that can be individually adjusted for any particular frequency range. The circuit
will take line level output from most any audio source, and operates on 12V DC. This
means that it can even be run in a car. (design idea circuit added 09/08) |
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3 Transistor Audio Amp 50 Milliwatt - Here is a little audio Amplifier similar to
what you might find in a small transistor radio. (added 4/02) |
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3: 5 Watt Class-A Audio Amplifier - Behaves like a one-valve operated Amplifier
Simple circuitry No cross-over distortion (added 3/05) |
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300 Watt MOSFET HI-FI Power Amplifier - The amplifier consists of two completely
separate monaural amplifiers each channel has its own power supply, resulting in zero
inter-channel cross talk, a common phenomenon in amplifiers sharing the same power
supply. In order to obtain the full output power each supply transformer should be
rated at 40VAC, 0, 40VAC at 640VA. Unlike many designs relying on the reservoir
capacitors to supply peak currents, I prefer to have the raw power available from the
transformer resulting in much faster transients. ….(circuit design added 11/08) |
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30w + 30w Amplifier - (electronic circuit added 08/08/08) |
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30W Class AB Amplifier - To set the above amplifier up, set R1 to max and R12 to
0. After doing this successfully, power on the amplifier. Set R1 so that the measured
output offset is between 30 and 100mV. Once set, adjust R12 slowly to achieve a
quiescent current of around 120mA. Keep checking the quiescent current as the amp
heats up as it might change due to voltage drop changes in the output devices caused
by heat. The heatsinks should be 0.6K/W or less for two amplifiers. ….(circuit design
added 11/08) |
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30W MosFet Audio Amplifier - This project was a sort of challenge: designing an
audio amplifier capable of delivering a decent output power with a minimum parts
count, without sacrificing quality. The Power Amplifier section employs only three
transistors and a handful of resistors and capacitors in a shunt feedback
configuration but can deliver more than 18W into 8 Ohm with <0.08% THD @ 1KHz at the
onset of clipping (0.04% @ 1W, 1KHz and 0.02% @ 1W, 10KHz) and up to 30W into a 4 Ohm
load. ….(electronic schematic added 11/08) |
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3-Band Equalizer - Using a single op-amp this easy to make equalizer offers three
ranges, low frequency, mid frequency, and high. With component values shown re is
approximately +/-20dB of boost or cut at frequencies of 50Hz, 1kHz and 10kHz. Supply
voltage may be anything from 6 to 30 Volts. Maximum boost 20dB ...(added 03/04/05) |
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3kHz Low Pass Filter Plus Audio AMP - This circuit uses a switched capacitor
filter IC from National Semiconductor to filter signals with frequencies higher than
the 3KHz needed for voice audio. The schematic includes an audio amplifier that is
designed to drive a standard audio head phone. The circuit is described in more detail
in the receiver section of Dave Johnson's Handbook of Optical Through the Air
Communications. (this link is off-site) ….(designed by David A. Johnson) |