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Amplifier Circuits:  Power Circuits
Power Amplifiers:  #'s - C        D - K        L - P         Q - S        T - Z

Amplifier -- Main Page

Last Updated: December 25, 2017 01:43 PM

Circuits Designed by Dave Johnson, P.E. :

Laser Light Detyector-10Mhz to 20Mhz   -  This circuit was originally designed to detect laser light pulses for an optical Ethernet communications system.  It has good ambient light immunity . . . Hobby Circuit designed by Dave Johnson P.E.-June 14, 2000

Light Receiver-10MHz to 20MHz   -  Light power to volts conversion = APPROX.15mV per microwatt at 850nM . . . Hobby Circuit designed by David A. Johnson P.E.-July 11, 2006

Low Power Amp Monitors Light   -  The circuit below takes advantage of a low power op amp with a “rail to rail” feature.  The single resistor R1 defines the light sensitivity of the circuit.  The output voltage is directly proportional to the intensity of light striking the small photodiode . . . Circuit by David Johnson P.E.-September 01, 2010

Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

Daisy MP3 player project -  The Daisy is a multipurpose sound player for embedded applications.  It can be used as a standalone personal music player,as the sound for an art project, in a kiosk, as a museum tour guide, in a toy, or anywhere that high quality embedded audio is desired.

Darling & DC Darling SE 1626 Amps -  This has become a very popular set of amp designs.  They are all based upon the 1626 Triode output tube and the philosophy to keep things SIMPLE.  I am continually amazed how good these amps sound for what they are.  The name "Darling" came from a good friend's description of my original design.  It looked like a miniature version of "full-sized" SE 300B.  The name stuck  Click  HERE  to find out more __ Designed by Bob Danielak

Darling SE Tube Amplifier -  I started this project with the idea to build a simple single-ended tube amplifier.  I didn't have any experience with the construction of tube amps so I was looking for a beginner's project.  Such a project should be simple (for easy debugging) and it should also be cheap.  Nobody likes to blow up a component of 300 dollars by a small lapse of attention __ Designed by Aren van Waarde

DC Coupled Phono Preamp -  Schematic, Only     Using 6SL7 instead, and DC-coupling of the two stages.  RIAA Preamp based upon the classic RCA 12AX7 design. __ Designed by Bob Danielak

DC Stabilized 1000uV/msec Op Amp -  Adding a discrete output stage provides full control of the circuit operating currents thereby obtaining very fast ac signal response.  The LT1001 is used to adjust the output dc offset to a very low value, uVs, not typical for very high speed amplifier designs. __ Linear Technology/Analog Devices App Note, Jun 21, 2011

Delay Unit for Surround Sound -  The Mitsubishi M65830 Delay IC has been discontinued (for reasons beyond my comprehension) , and so far a suitable replacement device has not been found.  This means (of course) that you will be unable to build this delay circuit.  I have left the project in place as reference, and the overall connection schematic is still valid if (when?) a replacement for the M65830 is located.  The project will be updated at that time.  In the meantime, just ignore the delay circuit __ Designed by Rod Elliott  ESP

Digital Volume Control -  This circuit could be used for replacing your manual volume control in a stereo amplifier.  In this circuit, push-to-on switch S1 controls the forward (volume increase) operation of both channels while a similar switch S2 controls __ Contact: IQ Technologies

Dip Oscillator for HF -  amateur radio construction projects. __ Designed by Peter Parker VK3YE

Direct Injection Box for Musicians -  Don't put up with hum.  This versatile DI box converts an unbalanced input to a balanced output signal and includes a 3-band equaliser. __ SiliconChip

Distance Sensing-devices for wireless distance & position Determination -  Since the early seventies we did build sonar devices to control our self made analog electronic music synthesizers.  In those years, simple to use transducers were not readily available on the electronic component market and so, we had to make our own, based on designs used for underwater hydrophones.  (Quarz crystals, inductive devices, self made condensor microphones etc...).  Although the focus of our research later on became doppler based sonar and radar movement detection and gesture analysis __ Designed by Dr.Godfried-Willem Raes

Distortion effects using an LM386 Audio Amplifier IC -  A few months ago, Aron Nelson released the Smash Drive.  The circuit ingeniously used an LM386 audio power amp chip to produce great distortion sounds.  Aron based his work on that of Tim Escobedo.  Tim's Stupidity Box was another great sounding unit and beautifully simplistic.  The Smokey Amp by Bruce Zinky was another design that used a 386 for some great sounds. __ Contact: holler @ runoffgroove.Com

DIY Bias Probe -  DIY Bias Probe __ Designed by Guitar Effect RC Keen

DIY Serial MIDI Interface 80C51/80C31 Version -  Run out of ISA card slots in your PC? Want a real MIDI interface instead of the toy interface that is built-into your sound card? Got a COM port handy? Then build the Serial MIDI Interface.  This page describes how to build this full-bandwidth single-port (one input and one output) MIDI interface.  The interface is buffered (that is, if the PC gets behind you won't lose data) and it works in Windows 3.1 and Windows 95 using a special (and very well-behaved) device driver.  A simpler version, using an Atmel AT89C2051 microprocessor, __ Designed by Paul Messick

Double D -  Two channels of buxom distortion. __ Contact: holler @ runoffgroove.Com

Drum percussion sensor Schematics -  The signals produced by most percussion sensors will require some processing before they're useful as triggers.  Usually this means converting an oscillatory signal into a single unambiguous pulse that is appropriately scaled to carry the widest possible range of velocity information to the circuit being controlled.  The circuitry in the diagram below performs this function. __ Designed by John Simonton

Drum Tone Oscillators -  The circuit shown is the most interesting of several drum oscillators on an analog sound board that appeared as part of an article in the June 1993 issue of Electronics Now.   Like most drum tone oscillators, the circuit is a very high Q resonant filter that is only slightly overdamped and on the verge of oscillating.  Triggering pulses (coupled through C5 and R5 in the circuit above) provide an excitation signal that "rings" the oscillatoran analog of the rapidly decaying envelope of percussion sounds __ Designed by John Simonton

DSP Musicolour Light Show; Pt.2 -  In last month's first part, we described the circuit operation of the DSP Musicolour.  In this instalment, we guide you through the construction.  The operation of the firmware and troubleshooting tips will be described next month.  In this issue there are also notes and errata for the schematic published last month. __ SiliconChip

DSP Musicolour Light Show; Pt.3 -  In last month's article, we detailed the construction of the DSP Musicolour.  In this month's article, we guide you through the final testing of the DSP Musicolour and give troubleshooting tips.  We also explain the operation of the firmware in more detail as well as discussing possible accessories. __ SiliconChip

DSP Musicolour Pt.1 -  This DSP Musicolour accepts audio input signals and drives coloured lights "in tune" with the music.  Its four output channels respond to different audio frequency bands and the brightness of the lights is in direct proportion to the amplitude of the frequency components.  A dot-matrix LED menu display is featured on the front panel and this also functions as a spectrum analyser or VU meter. __ SiliconChip

DSP Musicolour Pt.4 -  With a small and low-cost add-on PC board, the DSP Musicolour can be operated via an infrared remote controlvery handy if you want to use it in hard-to-reach places. __ SiliconChip

Dual Analogue Frequency Shifter -  An audio effects frequency shifter similar to the famous Bode/Moog design from the 1970s. __ Designed by Henry 

Dual parallel buffered effect loops with blend control. Schematic & perfboard/PCB layouts -  The Splitter-Blend provides two buffered parallel effects loops with a Blend control.  Also, a phase polarity switch is included to allow phase matching of the effect loops.  Possible uses are blending two sets of effects placed in the loops, a signal splitter, a simple mixer, or to blend an effect with the dry signal.  The phase inverter can be used for interesting results when mixing dry and effected signal. __ Contact: holler @ runoffgroove.Com

Dual Phantom Power Pre-Amp -  Schematic only, no circuit description __ Designed by John Simonton

Eight-watt Audio Amp -  Here is the schematic for an 8 watt audio amp.  This amp can be used as a simple booster, the heart of a more complicated amplifier or used as a guitar amp. __ Designed by Aaron Cake

Electric Guitar Preamplifier -  This is a circuit for a guitar preamplifier that can capture mechanical vibrations (any standard guitar pickup) and then convert them into an electrical signal.  The signal is then amplified by an audio amplifier. __ Electronics Projects for You

ElectricPickup -  I have an unused 900 MHz antenna sticking out of my chimney that has an ungrounded vertical element.  I replaced the 12 inch element with a two yard aluminum rod (see photo).  The antenna isonly 75 feet from the power lines so I didn't have much hope for this antenna to work.  The lead-in coax is long so its capacitance (about 1, 500 pF) forms a voltage divider with the capacitance of the antenna so the signal is significantly __ Contact: Charles Wenzel of Wenzel Associates, Inc.

Electronic Canary Sound Effects -  An electronic version of a chirping canary.  May be used as an alarm, a sound effects generator or perhaps a replacement doorbell __ Designed by Andy Collison

Electronic Church Bell Controller -  This circuit is a church bell controller.  Basic component is an ATmega32 microcontroller.  At the circuit 2 24LC32 eeprom memories is being used, the 1st for internal standard melodies and the 2nd one is for user's compositions.  This feature will be provided in the future __ Designed by Antonis Pontikakis © 03.10.2007

Electronic Metronome -  A metronome is used by musicians for practice in maintaining a consistent tempo, or rubato, around a fixed beat.  This circuit produces a regular beat at the rate of 40 to __ Electronics Projects for You

Electronic Metronome -  A Universal Power supply based on the L200 regulator, which includes an outboard pass transistor to boost output currents up to 4 amps. __ Designed by Volker Jeschkeit

Electronic Metronome with 555 -  This metronome circuit is not modern but is cheap and reliable.  The well known 555 is connected as an astable multivibratos in this electronic metronome and produces a regular train of impulses which can be heard with a speaker.  The metronome frequency can be adjusted with P1.  The power supply is a 9V battery and if you use a __ Designed by Popescu Marian

Emulate Mechanical Metronome -  08/19/99 EDN-Design Ideas The circuit in Figure 1 produces timing signals with a sound like that of a mechanical metronome. IC 1 is a 555 timer that oscillates at approximately 3200 Hz.  The two 3-kW resistors and the 0.047-µF capacitor set the frequency. IC 2 divIdeas the frequency of IC 1 's output by 2. IC 2 produces a square wave with an exact 50% duty cycle. __ Circuit Design by Jim Kocsis

Enhanced Linearity in the HELA-10 Power Amplifier -  AN-60033  Application Note __ MiniCircuits.com

Exponential Voltage-to-Frequency Converter for Music Synthesizers -  Logarithmic characteristic of BJT is used to provide an exponential control effect on V/F function.  By using a multiple transistor array, a thermal stabilization circuit assures a constant operating point for the log function. __ Linear Technology/Analog Devices App Note, Jun 21, 2011


Power Amplifiers:  #'s - C        D - K        L - P         Q - S        T - Z

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