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Variable Bandwidth CW Filter - As the sunspots return and DX propagation conditions to improve, the age old problem with QRM begins to show up on the amateur bands. Fortunately, help is at hand. The circuit in figure 1 is a variable bandwidth CW filter using two IC's. The first IC is a 741 op amp used as an active filter and the second IC is a 386 audio amp IC. This circuit connects to the headphone or speaker jack of your HF rig __ Designed by Radio Amateur Society of Norwich
Variable notch filter with both high & low pass filters - A variable notch filter with both high and low pass filters. __ Designed by Andy Collison
Various tube crossovers - You'll find here few ASCII schematics for Heath and Marantz tube crossovers. They were given in L'Audiophile No 11 old sery July 1979 __ ?
VCA-Voltage Controlled Amplifier - fantastic little circuit that can be configured as a vca, modulator and multiplier. __ Contact: P. Townshend EduTek Ltd
Versatile Audio Amplifier (Using the TBA810) - You can build a versatile audio amplifier for your workbench or for any other of your audio projects. with the TBA 810 IC (Integrated Circuit). It can also be cross-referenced to an NTE1115. You may view the data sheet of the IC HERE. It has special characteristics that make it quite attractive for the home constructor. From this IC, you will obtain different ranges of audio power, according with the supply voltages of your power source, as it is shown in the table below
Versatile FET booster engine. Schematic & perfboard/PCB layouts. - A versatile FET booster engine. __ Contact: holler @ runoffgroove.Com
Version #2 of my active HiFi speakers - Featuring new electronics, some new drivers, and lots of musings about audio technology. __ Designed by Manfred Mornhinweg
Vibrato Unit for Guitar - A reasonably simple circuit, with results similar to the Vox AC30 guitar amp __ Designed by G. Forrest Cook
Video Signal Edge Enhancements - I designed this circuit many years ago, based on the claims that the technique would improve the quality of standard TV images. The circuit adds information to the edges of the objects and was reported to bring out more detail. After building and testing. . . Circuit by David A. Johnson P.E.-July, 2000
Vinyl Amplifier - For those who might wish to 'save' to their computer hard-drive a digital copy of their own vinyl record collection, I have redrawn my 1975 vinyl pre-amplifier circuit. It remains __ Designed by Graham Maynard
Visual metronome - The Metronome is any device that produces a regulated audible and/or visual pulse, usually used to establish a steady beat, or tempo, measured in beats-per-minute (BPM) for the performance of musical compositions. It is an invaluable practice tool for musicians that goes back hundreds of years
VLF Whistler Reception - "Natural Radio" is a fancy name for radio noise with natural origins, mainly lightning. At first, you might think that listening to lightning crackles is pretty uninteresting but as it turns out, electromagnetic radiation from lightning can travel great distances and undergo strange modifications along the way __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Voice Amplifier - This is a very simple and low cost audio amplifier. Small modification in this circuit can be done to use along with walkman and intercom etc.
Voice Recorder ISD2560 - This project is based on ISD2560P IC which allows us to record 60 seconds voice and playback it with very high quality. As shown in the schematic, we input the voice by using an electret microphone. If a dynamic microphone is used, R2, R3, R4
Voice Recorder Module - Here's an improved version of the very popular voice recorder design we published in May 2005. It can now be set up easily to record two, four or eight different messages for random-access playback or a single message for 'tape mode' playback. Also, it now provides cleaner and glitch-free line-level audio output suitable for feeding an amplifier or PA system. It can be powered from any source of 9-14V DC. __ SiliconChip
Voice Scrambler/Descrambler - This is a single-inversion voice scrambler/descrambler. Though no longer useful for police scanners, it would be a fun project for a hobbyist. It was designed for use on a 9-volt battery, but by changing resistor values proportionately, it could be adapte __ Designed by Andrew R. Morris
Voice-Over - This is a circuit where a microphone and preamp circuit (voice circuit) have priority over any other audio signal. You can think of this as a one way intercom, if the main amplifier is used for listening to music, then when the push to talk switch is pressed, the amplifier is switched to the voice signal. __ Designed by Andy Collison
Voltage controlled Amplifier - In truth this, like many (most) VCAs is really a current controlled amplifier but there is really not too much difference since if you want to turn a CCA into a VCA you simply feed the current input from a voltage via a voltage to current converter (a. k. a. 'resistor') __ Designed by Richard Torrens
Voltage Controlled Panner - pans audio left and right __ Designed by G. Forrest Cook
Voltage Controlled Panner - This circuit is used to convert a mono audio signal into a stereo signal that can be panned between the left and right channel by a 0-10V control signal, it is intended for analog synthesizer systems. The circuit is mainly here for historical reasons, a higher quality panner may be built with the National Semiconductor LM13700 dual transconductance amplifier set up as a pair of voltage controlled amplifiers. __ Designed by G. Forrest Cook
Voltage follower with 1G ohm input resistance - This is a new implementation of the AVR DDS signal generator v2.0, already published in scienceprog. com. It is obvious that full credit for the original schematic and the firmware goes to its original creator. Presented here is a different PCB that is compact, single sided with only through-hole components for easy construction. __ Designed by Vassilis Papanikolaouvpapanik @ gmail.com
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 __ Designed by Aaron Cake
Volume Pedal Conversion - Volume Pedal Conversion for Wah Pedals __ Designed by Guitar Effect RC Keen
VOX (voice operated relay) - Schematic only __ Designed by va3iul
Vox AC30 Guitar Amplifier Simulator - This project has been withdrawn at Stephan's request, as he has sold the rights for the AC30 Simulator to a manufacturer. While its removal is obviously a loss for my site, I wish him well. Sorry for any inconvenience. __ Designed by Rod Elliott ESP
Vox AC-30 Top Boost adapted for use as a distortion stompbox - The Vox AC-30 amp is considered by many to be the defining sound of the British Invasion during the 1960s. The Top Boost circuitry provided crisp treble-laden overdrive that perfectly complemented the rich bass content. The English Channel is a JFET-based distortion stompbox that uses the same basic architecture as that classic early '60s amp. __ Contact: holler @ runoffgroove.Com
VU & PPM Audio Metering - A versatile and useful VU meter circuit, can also operate as a Peak Program Meter __ Designed by Rod Elliott ESP |
