A Better Volume Control -
A volume control using a
linear pot that is much better than most log pots . . .
Designed by Rod Elliott ESP |
Active Subwoofer & Controller - (electronic circuit added 7/03)
|
An Inexpensive Tone Encoder - Figure 1 illustrates an easy circuit that
can be constructed with mostly Radio Shack parts on any general purpose circuit
board. The only rigid requirement is that capacitor C1 be stable over a wide
temperature range. Use only Mylar, Polyester or Metal film for capacitor C1. The
frequency is determined by the following formula: FREQUENCY = 1/R1C1
The specified values should allow any tone between 100 to 300 Hz. Increase R1 or
add another resistor in series with R1 for lower tone frequencies. [Radio
Amateur Society of Norwich] |
AN543: Tone Generation - Microchip Application Note Published 26-Aug-97
(App Note added 2/06) |
Audio Graphic Equaliser - simple 7 band equalizer (added 4/02)
|
Audio amplifier output relay delay
- This is a simple circuit which I built to one of my audio amplifier projects to control the speaker output relay. The purpose of this circuit is to control the relay which turns on the speaker output relay in the audio amplifier...Tomi
Engdahl 1998 |
Audio Level Meter - Audio levels can be monitored using a small panel
meter with this circuit built from discrete components. The circuit has a
flat frequency response from about 20Hz to well over 50Khz. Input sensitivity is
100mV for a full scale deflection on a 100uA meter. Built on two common emitter
Amplifiers, the first stage has a preset resistor which may be adjusted for a FSD.
The last stage is biased to operate at roughly half the supply voltage for maximum
ac voltage swing. Audio frequencies are passed through the 10u dc blocking
capacitor and the full wave bridge rectifier converts the signal to a varying dc
voltage....(schematic design added 01/2010) |
Audio level meter VU Meter - This circuit uses just one IC and a very
few number of external components. It displays audio level in terms of 10
LEDs. The input voltage can vary from 12V to 20V, but suggested voltage is 12V.
The LM3915 is a monolithic integrated circuit that senses analog voltage levels
and drives ten LEDs providing a logarithmic 3 dB/step analog display. LED current
drive....(added 9/06) |
Audio Tone Control - designed by Aaron Cake (circuit added 7/02)
|
Audio Tone Controls - Many people at one time or other, regardless of
their interest in electronics, have adjusted these controls to suit their
preference. Whether its to boost the bass of their favorite CD, cut the noise /
static on a talk radio station or compensate for poor loud speaker response,
they've reached for the treble and bass tone controls. The ni....(circuit diagram
added 02/09) |
Automatic Loudness Control - Simple add-on module Switchable
"Control-flat" option (added 3/05) |
Baxandall Tone Control Circuit - by Ramon Vargas 8-11-04 |
Beetle Mk III - This project is based on our most stable FM transmitter.
It has a number of features, with a volume control to adjust the input level and a
small, neat box to make it easier to attach to a guitar. The volume control is
positioned at the end and when turned up fully, the transmitter provides fuzz
(distortion). (design added 08/08/08) |
Better Volume Control - how to create a log pot that is better than the
"real" thing . . . Designed by Rod Elliott ESP |
Build a simple, soft-action muting switch - 14-Oct-04 Issue of EDN
The circuit in Figure 1 adds a soft muting switch with power-up/power-down muting
to a line-level audio circuit. R4, C1, and JFET Q1 quietly ground a signal in 100
to 200 msec when you close S1 or release it when you open S1. Potentiometer R2,
set to twice Q1's cutoff voltage, makes the on/off transition times roughly
equal. [Design Idea by John Firestone, Bremerhaven, Germany] |
Delay Unit For Surround Sound - The Mitsubishi M65830 Digital 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 Delay Unit For Surround Sound - The Mitsubishi M65830 Digital
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…(circuit added 6/07) |
Digital volume control (Aaron Cake) - based on DS1669 Digital Pot IC
(added 8/03) |
Digital volume control has log taper - 11-Apr-02 Issue of EDN
Digital potentiometers provide a compact and convenient way to attenuate
audio-amplifier signals. However, most such potentiometers suffer from at least
one flaw a nonlogarithmic step increment. To avoid this problem, a user must
usually step the potentiometer in a nonlinear sequence to simulate a logarithmic
taper. [Design Idea by Doug Farrar, Los Altos, CA] |
|
|
Easy Parametric & Graphic Eq's Plus Peaks & Notches - (electronic
circuit added 8/02) |
Expandable Graphic Equaliser - The project described in this article is
a constant Q, fully expandable graphic equaliser. Where most "conventional"
graphic EQ circuits have a Q that is dependent on the setting of the pot, this one
maintains the same Q at all settings. This is achieved....(electronic design added
6/07) |
Guitar Control - CaStand-alone, 9V battery powered unit .
Three-level input selector, three-band tone control (added 3/05)
|