LA4440 Stereo Amplifier

LA4440 is a two channel audio power amplifier IC with inbuilt in dual channels enables it for stereo and bridge amplifier applications. In dual mode it gives 6 W per channel and in bridge mode 19 W output.

It has good ripple rejection of 46dB, small residual noise, built in over voltage and surge voltage protection etc. ideal feature of the IC is its pin-to-pin protection. Here LA4440 is wired in Stereo configuration using both inputs and outputs.
Features of LA4440

• Built in two channels to use as Mono and Stereo
• Dual mode 6W x 2 and Bridge mode 19W
• 46 dB Ripple rejection
• 18V Max. Power handling and 12V typical
• Good channel separation and low distortion
• Built in Audio Muting function and Pin-to-Pin protection
• Surge protection circuitry

Schematic of the LA4440 Stereo Amplifier Circuit

LA4440 datasheet

Assembled LA4440 Amplifier

                   Bass Booster

Here is a circuit of bass booster, boosts the beat frequency without effect the high frequency of the music. Bass booster is useful for those who want to hear music with some deep bass.

Circuit description of bass booster

This entire circuit bass booster is build and fabricated around a npn transistor and operational amplifier. Bass booster is divided into two major sections: One section is to bypass higher frequencies and another section is booster section.
The input signal from preamplifier circuit is given to input point of bass booster where higher frequencies will pass through capacitor C₁ and lower frequencies through R₁. IC₁ is used to boost the lower frequencies. Variable resistor VR₂ is used to control the boosting level. Switch SW₁ is given here is used to remove boosting effect. Output from bass booster is fed to power amplifier section.
Any overloading at output can be controlled by adjusting variable resistor VR₁.

NOTE: Grounding should be done perfectly to avoid any distortion.

PARTS LIST

Resistors (all ¼-watt, ± 5% Carbon)

R₁ = 150 KΩ

R₂ = 680 Ω

R₃ = 100 KΩ

R₄ = 220 KΩ

R₅ = 10 Ω

R₆ = 2.2 KΩ

VR₁ = 1KΩ

VR₂ = 10 KΩ

Capacitors

C₁, C₂, C₃ = 0.01 µF

C₄ = 10 µF/16V    

C₅, C₆ = 10 µF/12V

Semiconductors

IC₁ = µA751

T₁ = BC148

Miscellaneous

SW₁ = ON/Off switch

Digital Volume Control

              Digital Volume Control

This digital volume control has no pot to wear out and introduces almost no noise in the circuit. Instead, the volume is controlled by pressing UP and DOWN buttons. This simple circuit would be a great touch to any home audio project.

Schematic

Parts:

Part	Total Qty.	Description
C1	1	0.1uf Ceramic Disc Capacitor
U1	1	DS1669 Digital Pot IC (See Notes)
S1, S2	2	Momentary Push Button Switch
MISC	1	Board, Wire, Socket For U1

Notes:

1. U1 is available from Dallas Semiconductor.

 

2. S1 turns the volume up, S2 turns it down. 

 

3. The input signal should not fall below -0.2 volts. 

 

4. Using a dual polariity power supply (+-5V works fine) will cure most clipping problems. You will have to check the data sheet for the correct pins to connect your voltages.

10W Mini Audio Amplifier

              10W Mini Audio Amplifier

You can use this powerfull amplifier in any small audio project. It is very small (6.5 x 4.5 cm).It outputs 10W and uses a 9V battery.

           

Componets Layout                                             PCB

Componets List

R1 : 6 Ohm

R2 : 220 Ohm

R3 : nothing

R4 : 10 KOhm pontesiometer

C1 : 2200 uF / 25V

C2 : 470 uF / 16V

C3 : 470 nF / 63V

C4 : 100 nF

C5 : nothing

C6 : nothing

IC1 : TDA 2003

                                                                                                               

Speech Recorder

Speech Recorder  

 

PARTS LIST R1 = 1k R2 = 470k R3 = 10k R4 = 5k1 R5 = 4k7 R6,7 = 100k R8,9 = 1M R10 = 10R C1-10 = 100nF/63V C11 = 47nF/63V E1,4 = 220uF/16V E2 = 4u7F/16V E3 = 22uF/16V IC1 = ISD2560 + socket IC2 =LM78L05 IC3 = LM386 + socket MIC = Condensator microphone S1,2 = Pushbutton (S1 = Start and Pause. S2 = Stop and Reset) S3 = Change-over switch Hψjttaler = 8R speaker

The 2 pushbuttons = S1: Start/Pause. S2: Stop/Reset.

If you want to play your message, put S3 at Play. Then push S1 to start playing and again to pause.

If you want to delete your message press S2 twice.

If you want to record a message put S3 at Rec. Then push S1 to start and S2 to stop.