Audio Circuits: Level / Tone and Balance Circuits

2 Watt Amplifier 2

3 Band Equalizer

3 Band Equalizer

300 Watt Subwoofer Power Amplifier

45 Watt Single Chip Amplifier With Tone Controls

Active Subwoofer & Controller

Active Subwoofer

Audio Analyzer

Audio Graphic Equalizer

Audio Level Meter

Audio Output Level Meter

Audio Tone Control

Bass Amplifier

Battery Powered Stereo Balance Control Features Low Distortion Electronic Design - Ideas for Design / low-power, low-distortion circuit that can be used to balance the left and right headphones or speakers in battery-powered automotive or computer applications.

Better Volume Control How to create a log pot that is better than the "real" thing

Designing With the LMC835 Digital Controlled Graphic Equalizer National Semiconductor Application Notes,04-Nov-1995

Digital Delay Unit for Surround Sound

Digital volume control has log taper 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.

Digital Volume Control

Dual Channel Digital Volume Control

Electronic level

Graphic Equalizer #1

Graphic Equalizer #3

Improved PL tone Decoder

Inverted bipolar transistor doubles as a signal clamp A number of circuits, such as level detectors and AM demodulators, benefit from a rectifier with a low offset voltage. Silicon diodes have an offset of approximately 0.6V and do not work well in low-level circuitry. A Schottky diode is a bit better...

Mic Pre Pan Pot Circuit

Mono Audio Equalizer

Musical Instrument (Expandable) Graphic Equalizer (standard equalizer plus bonus distortion unit)

NHT Subwoofer Amp

One Pot to Control Two Channels

Parametric & Subwoofer Equalizer

Passive Filters Fill the Bill At Audio Frequencies (PDF contains multiple circuits - scroll to find this circuit.)

PC Speaker Volume Control Circuit

Pocket Equalizer for Headphone

Simple, Easy Parametric & Graphic EQ's, Plus Peaks & Notches

Soft Switching Amplifier With Tone Controls

Stereo Width Controllers

Subwoofer Equalizer: 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.

Subwoofer Filter: 12 dB/octave low pass filter for subwoofer, includes subsonic filter

Three Band Active Tone Control

Three Band Equalizer

Tone Control #2

Tone Controls With 2x NE 5532: check also PCB design and notes

Tone Detector

Tone Generator

Tremolo

Use Rotary Potentiometer To Drive Solid State Volume Control:- Electronic Design - Ideas for Design / This design idea details how a standard volume control can be replaced by its solid-state equivalent. Digital potentiometers are often advertised as replacements for rotary volume controls. To simulate these controls, many circuits employ up/down...

Voltage Controlled Panner: variable gain amplifier circuit ..