The SSM22111 is a high performance audio amplifier that delivers 1 W RMS of low distortion audio power into a bridge-connected 8 ? speaker load (or 1.5 W rms into a 4 ? load).

The SSM2211 operates over a wide temperature range and is specified for single-supply voltages between 2.7 V and 5.5 V. When operating from batteries, it continues to operate down to 1.75 V. This makes the SSM2211 the best choice for unregulated applications, such as toys and games.

Featuring a 4 MHz bandwidth and distortion below 0.2% THD + N @ 1 W, superior performance is delivered at higher power or lower speaker load impedance than competitive units. Furthermore, when the ambient temperature is at 25?C, THD + N < 1%, and VS = 5 V on a four-layer PCB, the SSM2211 delivers a 1.5 W output.

The low differential dc output voltage results in negligible losses in the speaker winding and makes high value dc blocking capacitors unnecessary. The battery life is extended by using shutdown mode, which typically reduces quiescent current drain to 100 nA.

Download the datasheet document of SSM2211 for 1.5W audio amplifier circuit reference:

SSM2211 Datasheet

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This is the circuit diagram of 24 Watt class A linear audio amplifier, built and tested by Marc Klynhans from South Africa. The supply voltage can be between 34V and 46V and the quiescent current should be set to 1.7A measured through R25 (a voltage of 0.75V must be measured over R25 for a quiescent current of just under 1.7A). R23 is a trimmer and must be set to maximum resistance (10kOhm) when powering up. Then the resistance of R23 must be decreased until the the quiescent current is achieved. If the amplifier is mounted on a big enough heatsink ( 0.6K/W at most) then the amplifier is very safe from thermal runaway. Intelligence must be used when choosing power and voltage ratings of resistors and capacitors.

24W Audio Amplifier (Class A) Specifications:

• 24W Class A into 8 Ohm
• 100mHz – 100kHz flat
• 305mV input for 24W into 8 Ohm (33dB gain)

Schematic Diagram:

Component part list:

PCB Layout:

Component Placement:

Take a note that this amplifier requires dual polarity power supply. Build the power supply using center tap transformer with output current 2A minimum and output voltage 30V, use about 6800 uF – 10000 uF electrolityc capacitors (elco). Good luck.

source: http://users.otenet.gr/~athsam/power_amplifier_35w_with_lm391.htm

Components List:

R1        : 39K 1/4 Watt Resistor
C1,C2     : 10uf 25V Electrolytic Capacitor
C3        : 100uf 25V Electrolytic Capacitor
C4        : 47uf 25V Electrolytic Capacitor
C5        : 0.1uf 25V Ceramic Capacitor
C6        : 2200uf 25V Electrolytic Capacitor
U1        : TDA1554Q Two Channel Audio Amp Chip
MISC      : Heatsink For U1, Binding Posts (For Output), RCA Jacks (For Input)

The? works best with 4 ohm speakers, but 8 ohm units will do. This circuit dissipates roughly 28 watts of heat, so a good heatsink is necessary. The chip should run cool enough to touch with the proper heatsink installed.

Operated at 12 Volts and at about 5 Amps at full volume. Lower volumes use less current, and therefore produce less heat. Printed circuit board is preferred, but universal solder or perf board will do. Keep lead length short.

The TDA1554Q is an integrated class-B output amplifier in a 17-lead single-in-line (SIL) plastic power package. The circuit contains 4 x 11 W single-ended or 2 x 22 W bridge amplifiers. The device is primarily developed for car radio applications.

Download TDA1554Q Datasheet Document:
[wpdm_file id=29]

Components list:

R1, R3 _________ 1K2 ohm
R2, R4 _________ 18 ohm
R5, R6 _________ 1 ohm
C1, C2 _________ 3u3 50V mini
C3 _____________ 22uF 16V
C5 _____________ 100uF 35V
C6, C7 _________ 220uF 10V
C10, C11 _______ 2200uF 35V
C4, C8, C9 _____ 100nF
IC _____________ TDA2009A
Heat sink

Circuit Specifications :

D.C. Input         : 8 ? 24V at 1 ? 2 A
Power output       : > 10W RMS /channel, 4 ohm load, 24V DC supply.
                     > 6W RMS /channel 8 ohm load 24V DC supply.
                     > 4W RMS /channel, 4 ohm load 12V DC supply.
S/N ratio          : > 75 dBA re. 10W output.
Frequency response : ~ 10 Hz to 50 kHz ?3 dB
Gain               : ~ 36 dB
Input level        : ~ 100 mV for full output

Circuit Works:
C1 & C2 are input coupling capacitors and block DC, as do C10 & C11 which are the output coupling capacitors, and C6 & C7 which block DC from the feed back loop. R1/R2 (and R3/R4) set the level of feed back.

The gain is equal to 1 +(R1/R2) = 68 or 37 dB. C8/R5 (and C9/R6) provide a high frequency load for stability where loudspeaker inductive reactance may become excessive. C4 and C5 provide power supply decoupling or filtering.

Kits:

The kits of this circuit is available at electronickits.com, you can order the kit there with online transaction.

Download 2x10W audio amplifier kit manual include the schematic diagram and the explanation:

10W Stereo Power Amplifier TDA2009A

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Download TDA2009A Datasheet Document:

TDA2009A Datasheet

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Components List:

R1, R2 = 120 ohm
R3, R4 = 2R2 ohm

C1, C2, C11, C12 = 220nF nonpolar capacitor
C3, C4, C5, C6, C7, C8 = 47uF/16V electrolytic capacitor
C9,  C10 = 470uF/16V electrolytic capacitor

IC = BA5406

The BA5406 contains two sets of AF power amplifiers. It delivers 5W x 2 into 3 ohm loads with a 12V supply. The BA5406 has good low-voltage characteristics, and the “pop” sound when power is applied is small. It generates little radio-band noise, minimal RF radiation.

Recommended supply voltage: 5-15V max. Typical 12V. Ideally the power supply should be able to deliver over 2.5Amps. This means that a typical “cheap” plugin power supply (wall wart) will not be good enough. The power supply leads should be as short as possible. Quiescent current 20-70mA, typically 40mA.

Download the manual of 2x3W Audio Amplifier with IC BA5406 in PDF version:

3W Stereo Audio Amplifier

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Download the BA5406 datasheet:

BA5406 datasheet

1 file(s) 141.54 KB

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Here is the circuit diagram of simple multitone alarm. This is a low cost circuit which is simple and easy to build. The main components of this circuit is based on dual op-amp MC1458 and LM 380. The two op amps inside the MC 1458 are used to produce square and triangular waves. LM 380 is used to amplify the output. The first op amp IC1a is wired as an astable multi vibrator and second op amp IC1b is wired as an integrator, to make the square wave triangle.

The two output square ans sine can be selected using switch S1 to the input of IC2 which amplifies it to drive the speaker. POT R4 can be used for tone adjustment.

Simple Multitone Alarm Notes

• IC1a and IC1b are same. So their power supply is common. Pin 6 of IC2 (inv input) has no connection.
• C1 and C2 are ceramic, C3 is electrolytic capacitor.
• A dual polarity power supply is needed here. Just need center tap transformer, bridge diode and an electrolytic capacitor. You may search the circuit in this site.

This document is the manual of 2x90W Stereo Tube Power Amplifier with EL34, model K4040 by Velleman. The document in PDF version contain of schematic diagram, part list, component guide, step by step how to build the circuit. This circuit is for advance hobbysts…

Stereo Tube Power Amplifier Features:

• Pure valve sound with high quality EL34 valves.
• High quality black and chrome housing.
• Chrome valve socket covers.
• Easy bias adjustment with LED indication.
• Removable bottom for easy access and service.
• High quality capacitors and components.
• Gold plated input and speaker terminals.
• Standby function.
• Soft start circuit for power transformer.

Stereo Valve Power Amplifier Specifications:

• 2 x 90Wrms in 4 or 8W.
• Up to 2 x 15Wrms full class A.
• Bandwidth: 8Hz to 80KHz (-3dB/1W).
• Harmonic distortion: 0.1% @ 1W/1KHz.
• Signal to noise ratio: >105dB (A weighted).
• Input sensitivity: 1Vrms.
• 115VAC or 230VAC / 500VA max.

Download the complete TUTORIAL of 2x90W Stereo Tube Power Amplifier with EL34 from the following link:

Stereo Valve Power Amplifier

1 file(s) 1.32 MB

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The circuit should be seen like this:

This is an exceptionally well designed amplifier, with a lot of power reserve, high fidelity, low distortion, good S/N ratio, high sensitivity, low consumption and full protection. Having all these almost ideal characteristics this amplifier is likely to become the basic building block of your future high fidelity system, or it can also become the element that will upgrade your existing system.

Schematic diagram:

Component part list:

PCB Layout:

Component placement:

Technical Specifications:

Output power (f=1 KHz, d=0.5 %): 100 W in 8 ohm
Supply voltage: ……………. ?? 40 V
Quiescent current: …………. 50 mA
Maximum current: …………… 2.6 A
Sensitivity: . 600 mV
Frequency response: ………… 10-35000 Hz (-1 dB)
Distortion HD: …………….. 0.01 %
Intermodulation dist.: ……… 0.02 %
Signal/noise: 83 dBConstruction

Go to this page for detailed explanation.

Download the explanation here