STEREO HEADPHONE AMPLIFIER USING LM4910

LM4910 belonging to the Boomer series of National Semiconductors is an integrated stereo amplifier primarily intended for stereo headphone applications. The IC can be operated from 3.3V ans its can deliver 0.35mW output power into a 32 ohm load. The LM4910 has very low distortion ( less than 1%)   and the shutdown current is less than 1uA. This low shut down current makes it suitable for battery operated applications. The IC is so designed that there is no need of the output coupling capacitors, half supply by-pass capacitors and bootstrap capacitors. Other features of the IC are   turn ON/OFF click elimination, externally programmable gain etc.

Circuit Diagram

Circuit diagram of the LM4910  stereo headphone amplifier is shown above.C1 and C2 are the input DC decoupling capacitors for the left and right input channels. R1 and R2 are the respective input resistors. R3 is the feed back resistor for left channel while R4 is the feed back resistor for the right channel. C3 is the power supply filter capacitor. The feedback resistors also sets the closed loop gain in conjunction with the corresponding input resistors.

Notes

• The IC is available only  in SMD packages and care must be taken while soldering.
• The circuit can be powered from anything between 2.2V to 5V DC.
• The load can be a 32 ohm headphone.
• Absolute maximum supply voltage is 6V  and anything above it will destroy the IC.
• A logic low voltage at the shutdown pins shut downs the IC and a logic high voltage at the same pin activates the IC.
  

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Stereo STK013 audio amplifier circuit

On the amplifier circuit using ic STK, the same as my previous posting. However, in the above circuit has 2 inputs and 2 outputs, or commonly called a stereo amplifier. This issue of power amplifier 2 x 18Watt and has impedance 8. To stress that it takes about 35-38Volt.

Component list :
Resistor
R1 =  390K
R2 = 390K
R3 = 220K
R4 = 220K
R5 = 220K
R6 = 220K
R7 = 100R
R8 = 1R
R9 = 9.1K
R10 = 9.1K
R11 = 1R
Capacitor
C1 = 10uF
C2 = 10uF
C3 = 0.47uF
C4 = 0.47uF
C5 = 220uF
C6 = 0.047uF
C7 = 4700uF
C8 = 100uF
C9 = 1000uF
C10 = 100uF
C11 = 4700uF
C12 = 470uF
C13 = 0.047uF
IC
U1 = STK013

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Sony Car Stereo

The Sony Corporation, based in Tokyo is a leading manufacturer of audio, video, communications, and information technology products for the consumer and professional markets. Their music, motion picture, television, computer entertainment, and online businesses also make Sony one of the most comprehensive entertainment companies in the world. 

So it is not surprising to learn that Sony car stereos are also well renowned in the automotive audio market. In 2005, Sony car stereos launched their latest carrier car audio product, the Sony car stereo Xplod series which has an amazing lineup of head units, speakers, amplifiers, subwoofers, changers and accessories. It is impressive both in performance and aesthetic value. 

Sony car stereo Xplod Series

A good head unit from the Sony car stereo Xplod Series is the CDX – M9900 CD Receiver/Changer Controller/MP3 Player which boasts these features:   

- 32,000-color TFT display

- Video Input for External Source Playback

- CD/CD-R/CD-RW/MP3 playback

- 4-Volt F/R/Sub Preouts w/HPF & LPF

- 52W x 4 High Power

- CEA-2006 Power Compliant

- CD/MD Control, CD Text

- XM Ready

- BBE MP, DSO, EQ7

- Auxiliary Input

- 1-bit D/A Converter

- Drive-S with 120dB S/N Ratio

- SSIR-EXA tuner, 18FM & 12AM presets

- Red key illumination

- Supplied wireless card remote (RM-X145A)

- Optional wireless rotary remote (RM-X6S)

- Optional wired rotary remote (RM-X4S)   

This Sony car stereo goes best installed with matching items from the Xplod series such as: 

Sony car stereo XS – V6941H 6 x 9” 4 - Way Speakers: 

- 6 x 9" HOP Woofer Cone

- Stroke Stabilizer Surround

- 2-5/8" Cone Mid

- 1" Balanced Dome PEI Tweeter, Super Tweeter

- 400W Peak Power (100W RMS)

- Flexible Mounting Options 

Sony car stereo XM-2100GTX 2/1 Channel Amplifier:

- 600W Max Power

- 100W x 2 RMS into 4 ohms, 20Hz-20kHz @ 0.04% THD

- 250W x 1 RMS into 4 ohms, 20Hz-20kHz @ 0.1% THD

- CEA-2006 Power Compliant

- Variable 50 - 300 Hz low pass filter

- 40 Hz EQ boost

- MOSFET power supply

- RCA & speaker level inputs

Sony car stereo XS-L102P5 10” Subwoofer: 

- 10" Polypropylene Cone

- 1200W Peak Power (330W RMS)

- Unique cone design offers superior rigidity

- Gold-plated Binding Posts

- Small sealed/bandpass enclosure optimized

- 4-Ohm Voice Coil

- 2005 Subwoofer Parameters

Like other modern car audio manufacturers, the Sony car stereo also offers video capable units for playing VCDs, DVDs. A good item from the Sony car stereo Dream System Series is the MV - 900SDS Mobile DVD Dream System. 

- 9" wide Lcd TFT display with swivel function

- DVD/CD-R/RW/VCD/MP3 Playback

- Built-in wired FM modulator

- Reversible display image

- Slot-load DVD Mechanism

- Memory Stick® media for playback of JPEG, MPEG, MP3

- Built-in Stereo Speakers

- A/V Input

- A/V Output

- Optical Digital Output (Dolby Digital®, dts®)

- IR transmitter for wireless headphones

- 2 sets of wireless headphones included

- Wireless card remote included

This unit is encased in a grey metallic finish and is ideally attached on the ceiling of the vehicle. 

It is also an amazing fact that a lot of enthusiasts also incorporate the PlayStation into their Sony car stereos, which is probably one of the reasons why the Sony car stereo system has earned quite a following.     

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Stereo TDA2822 audio power amplifier circuit

In this series I use IC tda2822M as the main amplifier, but if you want to use in addition to IC TDA2822M you can use ic I mentioned this is KA2209, NJM2073, U2822B, U2823B. Output is issued no more than 4W, which had low output. Supply voltage from 3 volts to 16 volts.

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Build a BTL Stereo Amplifier Wiring diagram Schematic with TDA7052

Build a BTL Stereo Amplifier Circuit Diagram with TDA7052 , you can see schema and start make a BTL Stereo Amplifier Circuit Diagram with TDA7052.

BTL Stereo Amplifier Circuit Diagram with TDA7052 

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2 x 2W STEREO AUDIO AMPLIFIER

Circuit Diagram

Layout 2 x 2W STEREO AUDIO AMPLIFIER

Circuit Diagram for 2 x 2W STEREO AUDIO AMPLIFIER

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200W Stereo High Power Amplifier LM3886

This audio amplifier designed uses two LM3886 per channel, in parallel circuit, based on the PA100 parallel amplifier detailed in National Semiconductors application note - AN1192. This amplifier can deliver about 50W into a 8-ohm speaker and 100W into a 4-ohm speaker. This is a stereo amplifier and therefore 4 LM3886s are used.

The LM3886 circuit is in a non-inverted configuration, so the input impedance is determined by the input resistor R1, i.e. 47k. The 680 ohm and 470pF resistor capacitor filter network is used to filter out the high frequency noise at the RCA input. The 220pF C4 and C8 capacitors are used to shot out the high frequency noise at the LM3886 input pins.

I used high quality audio grade capacitors at several locations: 1uF Auricap at the input for DC blocking, 100uF Blackgate for C2 and C6, and 1000uF Blackgate at the supply filter.

LM3886 Power Amplifier Schematics

The PCB is designed in a way that the power ground is separated from the signal ground, as you can see from the below layout. The signal ground is located in the middle and surrounded by the power ground. There is a thin trace near C5 connecting them. The PCB layout is done by using PADS PowerPCB 5.0. I think it is a powerful layout software.

Amplifier Printed Circuit Board (PCB)

Amplifier Printed Circuit Board Bottom

Amplifier Printed Circuit Board Top

Amplifier Printed Circuit Board

Amplifier Power Supply
The power supply used is a regulated power supply. I used 10000uF per rail before the LT1083 regulator. After the regulator, I have 100uF on the regulator board. The advantage of using regulator is that the power supply ripple voltage is removed. If power regulation is not used, I can hear very little 50/100Hz hum from the speaker.

The high current MUR860 diode is used to ensure high current flow. The voltage regulator used is LT1083, it can provide about 8A of current. Transformer used here is a 500VA 2x 25V. The power supply is then regulated by 2 LT1083, after the regulation, the voltage is 30V.

Power Supply Recomended

I did some DC measurement and the result is quite good, I got 7 mV of DC offset at the speaker terminal. The voltage difference between the output of the 2 chips is less then 1 mV.

The sound of this amplifier is similar to my LM3875 amplifier, which is very clean and detail. It has no hum, no hiss and no noise. Compared to the LM3875 Gainclone, this amp can deliver twice the power to my 4-ohm speaker, and it improves the dynamics and bass punch a lot.

Source :http://www.shine7.com/audio/pa100.htm

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Stereo balance tester

Description

The meter will show volume and tone control balance between left and right stereo amplifiers. For maximum convenience the meter is a zero-center type. Resistors are five percent or better and the diodes a matched pair. Optimum stereo level and phase balance occurs for matched speakers when the meter indicates zero. If the meter indicates either side of zero, the levels are not matched or the wires are incorrectly phased. Check phasing by making certain the meter leads are connected to the amplifier hot terminals and the common leads go to ground.

Circuit Diagram

Stereo balance tester  

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12W HiFi Stereo Audio Amplifier

Here is the schema of a 2X12 watt HiFi stereo audio amplifier schema using IC TDA 2616 from Phillips. A quiet simple and robust schema using very less components. This makes the schema ideal for a portable power amplifier. The schema delivers 12 W power on 8 Ohm speaker for each channel at +/- 12 V dual supply.

The TDA2616 is a stereo power amplifier IC comes in a 9-lead single-in-line (SIL9) plastic power package (SOT131). This IC is specially designed for mains fed amplifier diagram, such as stereo radio, tape and television . The IC has good gain balance of both channels and Hi-fi in accordance with IEC 268 and DIN 45500 standards. Also the IC TDA 2616 has special inbuilt schema for the suppression of noise signals at the inputs, during switch-on and switch-off. This prevents click sounds during power on and power off.

Notes.

• All capacitors except C10 & C9 are ceramic.
• All capacitors must be rated 50V.
• Use a well regulated and filtered +/- 12 V dual power supply that is able to provide at least 2 A continuous current.

TDA 2616 Pin assignment & layout.

source: diagramtoday.com

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