Audio Circuits

High Gain Stereo Tube Preamplifier

2012-01-28T08:46:00.000-08:00

This is the circuit diagram of stereo tube preamplifier, give you high gain with high performance output. This circuit should work fine with a 6J5, 12SX7, 6CG7, or 12AU7 as the lower tube, and a 6BX7, 12B4, or triode-connected 6BQ5 as the upper tube. Any of the miniature TV dual triodes such as 6DE7 or 6EW7 can serve as both top and bottom triodes since they contain a medium-mu and a low-mu section. (This wouldn't be my choice, since the octals seem to sound better, but you may choose the tubes you like.)

Tube Preamplifier Parts List:

R1,R5 = 100 1/4W carbon
R2,R6 = 100 1W metal film
R3 = 1M 1/4W metal film
R4 = 10k 25W wirewound
R7 = 10k 1/2W metal film
VR1,VR2 = Part of Alps quad volume/balance control
C1 = 2uF 400V polypropylene
C2 = 10uF 400V polypropylene
V1 = 12SN7GT (GE) or 6SN7GT (see text)
V2 = 6BL7GT (GE)

This circuit require special power supply circuit. The power supply is regulated, has slow warmup inherent in its operation. The power supply for this tube preamplifier is in simply designed. The tube 6AS7G for looks; it's much bigger and lights up more impressively than a 6080. The only problem was with the voltage standard since gas tubes are capable of impressive noisemaking.

Power Supply Parts List:

R1 = 10 1/2W metal film
R2,R3 = 20k 10W wirewound
R4 = 10k 1/4W metal film
R5 = 18k 1/2W metal film
R6 = 56k 2W metal film
R7 = 27k 2W metal film
C1 = 10uF 400V polyprop
C2 = 220uF 400V electrolytic
C3 = 0.1uF 400V Mylar
C4 = 2uF 400V polyprop
T1 = power transformer, 250-0-250V 50mA, Thordarson 24R09 or similar
T2 = filament transformer, 24V CT 2A, Mouser 41LK020 or similar
L1 choke, 20H 50mA, two Triad C-3X in series (see text)

Other components needed: (8) ceramic octal sockets, (5) 7-position ceramic terminal strips, (6) chassis-mount RCA sockets, aluminum chassis 15" 4" 3", AC power cord with strain relief, knobs for pot, DPDT miniature switch, Teflon-insulated wire, 1/4" copper tubular braid, stereo 1/4" panel-mount phone socket, assorted hardware.

Read more about High Gain Stereo Tube Preamplifier, visit this page

2x6W Stereo Audio Amplifier based LA4440 Power IC

2012-01-21T01:58:00.000-08:00

This is the diagram of 2x6W stereo audio amplifier based LA4440 power IC. Actually, the LA4440 can be used in both stereo mode and mono (bridge) mode, but the circuit presented in this post is LA4440 in stereo mode. The recommended power supply is 13.2V, while the maximum voltage rated at 18V.

LA4440 Features:

Built-in 2 channels (dual) enabling use in stereo and bridge amplifier applications.

Dual : 6W´2 (typ.)
Bridge : 19W (typ.)

Minimum number of external parts required.
Small pop noise at the time of power supply ON/OFF and good starting balance.
Good channel separation.
Good ripple rejection : 46dB (typ.)
Low distortion over a wide range from low frequencies to high frequencies.
Small residual noise (Rg=0).
Easy to design radiator fin.
Built-in protectors.
Built-in audio muting function.

Thermal protector
Overvoltage, surge voltage protector
Pin-to-pin short protector

50W Power Amplifier Circuit using STK084

2012-01-13T04:26:00.000-08:00

This is the circuit diagram of 50W power amplifier circuit which built based on single power amplifier chip of STK084. It's an well-known old IC for audio frequency (AF) amplifier.

This circuit requires dual polarity / split power supply with maximum supply of ± 50. The recommended supply is ± 35 / 2-3A DC current. You may use this split power supply circuit for the amplifier. Use 28V center tap transformer to get about ± 36V output.

Technical Details:

Power output: 50W
RL : 8 Ohm
TDH : 0.2 %
Rin : 52K
Gain : 26.4 dB
Noise : 0.3 mV

Take a note that heatsink is required to be mounted on the power IC since it will going to hot when operated and deliver high power output (high audio volume level).

50W Audio Amplifier Circuit

2012-01-08T02:38:00.000-08:00

Here the 50W audio amplifier circuit diagram. The amplifier is based ICL8063. This a good amplifier circuit which is easy enough to built.. This circuit can be connected by radio, TV, stereo or other devices.

The circuit is also featured with inputs for the record player, guitar, microphone, and others. If you add low pass filter at the input, it will work like a mini-subwoofer. Circuit scheme presented will guide you in 50W amplifier construction, good luck.

The power supply is splitted type, already added on above circuit diagram.

Components List:

R1 = 200R 1/4W
R2 =200K 1/4W
R3 = 30K 1/4W
R4 = 1K 1/4W
R5 = 5K 1/4W
R6, R9 = 1M 5% 1/2W
R7, R8 = 0,4 ohm 5W
R10 = 10K Pot
R11, R12 = 51K 1/4W
R13 = 47K 1/4W
C4, C6, C5, C7, C8 = 1nF
C9 = 50pF
C10 = 0,3uF
C11, C12 = 10000uF/50V
U1, U2 = IC 741 Op Amp
U3 = ICL8063
Q1 = 2N3055 NPN Power Transistor
Q2 = 2N3791 PNP Power Transistor
D = 250V 6A Bridge Rectifier
T = 50V Center Tapped 5A Tranformer
C1 = 100uF/35V
F1 = 2A Fuse
C2 = 11nF
SPEAKER = 8 ohm 50W
C3 = 3750pF
Heatsinks For Q1 and Q2

Enhanced Hafler Matrix Surround Sound Decoder

2012-01-02T14:19:00.000-08:00

This is the circuit diagram of enhanced Hafler Matrix surround sound decoder. The above schematic can be a basic technique to attain exactly the same factor (with some extra rewards) at line level (i.e. prior to the signal reaches the power amplifiers - in a bi-amped method, this circuit should be in between the preamp along with the electronic crossover). The extras obtainable are readily apparent:

Wiring is simplified (despite the fact that extra power amplifiers are necessary)
We now have a centre channel signal accessible
Provision for a mono signal to a sub-woofer is simple

Though there have been comparable circuits published more than the years, this can be slightly unique in several locations. I wanted to prevent getting any active electronics inside the key Left and Right channels, due to the fact this eliminates any possibility of sound degradation because of the introduction with the op-amps. The input impedance of 50k won't pose an issue for any pre-amp (such as valve sorts), as well as the principal signal is merely in parallel using the extra circuitry.

No volume control has been integrated, due to the fact you already have one inside the pre-amp circuit. It would just turn into one more component to fiddle with, and due to the fact it could be hardly ever applied, would most likely develop into noisy as time passes.

How the Circuit Works
Opamp U1A is connected as a subtracting amplifier. Really should exactly the same signal be applied to each inputs, the output is zero. Because of this, it'll eliminate all popular data from the stereo signal, and reproduce only the distinction signal - in specifically exactly the same way as the original Hafler style.

U1B is actually a straightforward summing amplifier, along with the output consists of all of the info from each the left and appropriate channels. A possibility that springs to thoughts is the fact that we could then subtract the distinction information and facts from this output, to ensure that only material that's definitely typical to each channels will be reproduced. Would this enhance the efficiency for the extent that the added circuitry is warranted? I have a tendency to doubt it, but will appear into this additional.

Centre Channel Control
The pot (VR1) would be to set the centre channel level. This may be a trimpot, or perhaps a standard pot mounted in the rear (to assist stop "fiddlers" from mucking up the settings you like). I've observed circuits which don't involve this, which appears generally a poor concept. When the two channels are summed, the centre channel will ordinarily have a degree of -3dB relative for the left and right channels - supplied the signal isn't mono. Centre channel speech (for instance) will probably be mono, so the level will probably be equal to that of every single from the most important speakers. Given that the centre channel amp and speakers are hardly ever as strong as the primary Left and Right channels, there is certainly a distinct possibility of overload with the amp, the speaker or each.

Due to the fact the centre channel is supposed only to fill the "hole" and offer a stable centre sound image, it will not must be as loud - particularly because it'll practically undoubtedly have inferior sound superior towards the principal speakers and will thus degrade the overall sound excellent. The level manage will permit you to set the level to just adequate to supply the stable sound image, and no much more.

The capacitor (C1) is optional. It gives a nominal 8kHz roll-off frequency (that is apparently rather regular for "real" surround-sound processors). This assists to minimise any disturbance towards the most important stereo signal, but really feel free of charge to leave it out, given that most centre channel speakers almost certainly will not be capable of reproduce considerably above this frequency anyway.

Sub-Woofer Output
The sub-woofer output is merely taken directly from the centre channel mixer, and I integrated no low-pass filter simply because I do not know of any sub which doesn't have a filter already. Adding a different one basically adds unnecessary complexity, and will introduce phase shift in the output that a phase compensation circuit (usually integrated in sub woofers) may possibly not have the ability to cope with.

Miscellaneous
The 100 Ohm resistors inside the outputs are to stop the capacitance in the signal leads causing the opamps to oscillate. At this value, they are going to lead to no high frequency loss, unless you insist on 100m lengthy signal leads (in my expertise, these are uncommon).

It'll also be noticed that you will discover two outputs for the rear speakers, merely in parallel. I integrated this simply because it can be less difficult to wire if the user is connecting a stereo amp for the rear speakers. Naturally, a mono amp will do just fine, so long as it's capable of driving the two rear speakers in parallel. This could not be probable if the speakers are 4 Ohm forms (these are becoming a lot more popular in hi-fi, so its not that silly).

The enhanced Hafler Matrix surround sound decoder circuit source page: http://english.cxem.net/equaliser/equaliser6.php

Low Noise Stereo Preamplifier based NE5533

2011-12-25T15:46:00.000-08:00

This is the circuit diagram for low noise stereo preamplifier based on NE5533 operational amplifier. The circuit uses 2 pieces of NE5533 since there is only 2 op-amp circuits inside NE5533. This circuit is featured volume level, right/left balancing and loudness level adjustment. It will be easy to build this circuit since the components used in this circuit is not much and easy to find at electronic store.

About NE5533:

The NE5533 is dual/stereo high-performance low noise operational amplifiers. Compared to other operational amplifiers, such as TL083, they show better noise performance, improved output drive capability and considerably higher small-signal and power bandwidths. The single op-amp version is NE5534.

This makes the devices especially suitable for application in high quality and professional audio equipment, in instrumentation and control circuits and telephone channel amplifiers. The op amps are internally compensated for gain equal to, or higher than, three. The frequency response can be optimized with an external compensation capacitor for various applications (unity gain amplifier, capacitive load, slew rate, low overshoot, etc.) If very low noise is of prime importance, it is recommended that the 5533A version be used which has guaranteed noise specifications.

Download the NE5533 datasheet here.

22W Audio Amplifier with TDA1554

2011-12-18T20:00:00.000-08:00

Here the 22W audio amplifier which is low cost and very easy to build. You can use this circuit as a booster in a car audio system, an amplifier for satellite speakers in a surround sound or home theater system, or as an amplifier for computer speakers

Circuit Notes

Use 4 ohm speakers for best performance, but 8 ohm units can be used too.
The circuit dissipates roughly 28 watts of heat, so a good heatsink is necessary. The TDA1554 chip should keep cool enough to touch with the proper heatsink installed.
The circuit works at 12 Volts at about 5 Amps at full volume. Lower volumes use less current, and therefore produce less heat on the TDA1554 chip.
Construction on Printed circuit board (PCB) is preferred, but universal solder or perf board will do since the design is very simple. Keep lead length short.

Parts List:
R1 = 39K
C1,C2 = 10uf/25V
C3 = 100uf/25V
C4 = 47uf/25V
C5 = 100nF
C6 = 2200uf/25V
U1 = TDA1554

2 Way Active Speaker with STK4042

2011-11-22T22:14:00.001-08:00

Active speakers have many advantages over the simple speakers using passive materials for implementing the components separation of frequencies. In the case of active speakers have proportionally higher manufacturing costs, since each loudspeaker is driven by its own amplifier. In a properly designed active speaker, the sound quality is much better and very low distortion, because it uses inductors and capacitors in the signal path,. Those capacitors are on the path of the signal have a very small price and very good quality. This does not mean that a well designed passive speaker is good, maybe better than an active. Unlike an active speaker is much more difficult to manufacture.

In [Fig.1], is an active channel speaker 2-way. As shown in the Block diagram [Fig.2], is a classical crossover 2-way crossover fc = 3100HZ -24dB/oct. This frequency was chosen because it is near the crossover of many speakers of trade, but can be changed and customized to your choice of speakers, enough to use the formulas give for the calculation [Fig.3]. The IC1 makes the adjustment input filters around the IC2 create a high pass filter frequency for frequencies above Fc = 3100HZ, contrast material around the IC3 create a katodiavato filter for frequencies below 3100HZ. With the trimmer TR1 in the line of high frequency can be adjustable, if necessary, the level between the two loudspeakers. You will usually need to be lowered by 10% the level of the tweeter than the woofer. In many parts of the filter capacitors and resistors are not used, but it's there for future changes, another crossover as the R6-10 not used.

In the next stage the two outputs of the filter led to two power amplifier in IC4 for high frequencies and IC5 for low. These are two of Sanyo hybrid integrated output 80W/8ohms with very good features and sound. Can be changed to another type of series as STK4036, STK4038, STK4040, with a corresponding modification of power supply. This series is used in many cases active speaker with very good audio results. Good is to use the formula STK4042XI, because it has more modern interior design in relation to the type STK4042II. The filters RLF1-2 at the output of amplifier consisting of the resistor R27 and R38 and a coil wrapped around it in three layers. The coil is made with 25 to 30 turns of copper wire with a diameter of 1mm. In the output amplifiers are the contacts of relay RL1, which is controlled by the DC protection and delay. This circuit is located around the IC6 and works as follows: When the circuit is powered by a tendency there is a delay of 5 sec to connect the speaker outputs on the amps so they do not hear the noises of charging capacitors. Unlike when you stop feeding the circuit then RL1 disconnect quickly the speakers from the amplifiers, so they do not hear the noise discharge of capacitors. While the circuit protects speakers from continuing trends that will occur for any reason, the output of power amplifier , opening the contacts of RL1 and disconnecting very fast loudspeakers.

The circuit protection is evident from Led [D20], which should be placed prominently on the speaker box. The wiring is shown in Fig.2. The AC cord is toroidis good quality. The mainboard, the heatsink, the power transformer, bridge rectifier BR1, as well as all materials that appear outside board mounted on an aluminum block suitable size which adapts to the dimensions of the box and put the speaker on the back of the box. The two amplifiers IC4 and IC5 are screwed onto the back of the heatsink. The overall efficiency of the speaker always depends on the characteristics of units Tweeter and Woofer which used to it, as well as the design and quality of the box. Earliest used in place of the tweeter and woofer T33A B200G of the KEF.

Part List

R1-21-32-25-36-58=1 Kohms	C19-20-52=10uF 25V	IC1=TL071
R2=47 Kohms	C21-35=470pF	IC2-3=TL072-NE5532
R3-4-5-7-8-9-46=22 Kohms	C22-36=470nF 63V MKT	IC4-5=SKT4042[XI] or [II]*See text
R6-10=N.C *See text	C24-25-26-38-39-40=100pF	IC6=4093
R11........18=22 Kohms	C27-41=10pF	IC7=7812T
R19-20=47 ohms	C28-42=100nF 100V MKT	IC8=7815T
R22-33=33 Kohms	C29-43=1nF 63V MKT	IC9=7915T
R23-24-34-35=100 ohms	C30-34-44-48=100uF 63V	RL1=Relay 12V [G2R2 Omron]
R26-37=0.22 ohms 5W	C31-45=220uF 25V	RLF1-2=*See text
R27-38=10 ohms 3W	C32-33-46-47=10uF 63V	F1-2-3-4=1.6A FAST 5X20mm
R28-39=6.8 ohms	C49=47uF 25V	F5=1A SLOW 5X20mm[Fig.2]
R29-40=12 Kohms	C50-51=100nF 63V MKT	T1=220V//A=2X30V 250VA B=2X15V 30VA [Toroidal]
R30-41-53-54=10 Kohms	C53=1uF 25V
R31-45=560 ohms	C54=3.3uF 25V
R44-45=1 Mohms	C55-56-58-59=33uF 63V	JF1=3pin male supply jack
R47=39 Kohms	C57-60=22uF 16V	JF2=Female RCA Jack
R48-50=15 Kohms	C61-62=15000uF 63V AXIAL	J1-3=2pin conn. with 2.54mm pin step
R49-51-52-55=56 Kohms	C63-64=2200uF 25V AXIAL	J2=3pin conn. with 2.54mm pin step
R56-57=3.9 Kohms	C65-66-67-68=100nF 63V MKT	J4=3pin conn. with 3.96mm pin step
R43=470 ohms 1W	Q1=BD679	J5=4pin conn. with 3.96mm pin step
TR1=47 Kohms trimmer horizontal	Q2-3=BC550	T=Tweeter 8ohms 50 until 80W
C1-22-36-23-37=1uF 63V MKT	D1-2-3-4=1N4002	W=Woofer 8ohms 50 until 100W
C2=390pF	D5=8.2V 0.5W Zener	BR1=Bridge rect. 400V 25A [Fig.2]* See text
C3-4-7-8-14-15=100nF 63V MKT	D6=1N4148	BR2=Bridge rect. 100V 1.5A
C5-6-9-10-11-12=3.3nF 63V MKT* See text	D7.....19=1N4148	All resistors is 0.5W 1% metal film except for announce differently
C13-16-17-18=3.3nF 63V MKT*See text	D20=5mm LED [Fig.2]

2 Way Active Speaker with STK4042 source: http://users.otenet.gr/~athsam/2_way_active_loudspeaker_eng.htm

TDA2030 : 15W OTL Audio Amplifier Circuit

2011-11-11T16:33:00.000-08:00

This is the circuit diagram of 15W OTL audio amplifier based single power IC TDA2030.

The TDA2030 is a popular power chip for low power amplifier circuit. The circuit will deliver about 15W audio power when use 8ohm loudspeakers. For maximum power output, you need 24VDC power supply with 1A current, for single/mono channel. Use power supply with 2A minimum output current for stereo channel. Do not forget to mount a heatsink on the IC.

15W OTL Audio Amplifier PCB design

Class-AB Headphone Amplifier Circuit

2011-11-01T04:36:00.000-07:00

This is the circuit diagram of Class-AB headphone amplifier which built using 3 transistors of BC549 and BC559. The circuit is very simple and will give you good audio performance.

The power consumption of this headphone amplifier circuit is claimed to be very low. Two pieces of AA battery will supply the circuit for long time.

Components List:

R1 - 100K
R2 - 330
R3 - 100
R4 - 22 (2 - 4.5V)
R4 - 100 (5 - 12V)
C1 - 4.7uF

C2 - 4.7uFC3 - 100 - 1000uF
C4 - 220uF
P1 - 100K
D1, D2 - 1N4148
Q1, Q2 - BC549
Q3 - BC559

Specifications:
Power Supply Voltage: 2 - 12V
Power Consumption: 10mA/3V - 30mA/12V (measurements taken using a stereo version)
Output Power: 300mW

The circuit can be used for common electronic devices such as radios, CD/DVD Players, computers, audio/video players, ipods etc.

Circuit Source: Class-AB Headphone Amplifier Circuit

60W Class AB Audio Amplifier with TDA7294

2011-10-26T04:39:00.000-07:00

Here is the circuit diagram of 60W class AB audio amplifier which is built based power IC TDA7294. The TDA7294 amplifier module is a monolithic integrated circuit. It's meant for use as an audio class AB amplifier in hi-fi applications. It has a wide voltage range and output current capability, enabling it to supply the highest power into both 4 ohm and 8n ohm loads. Using the addition of a handful of components and also a appropriate power source, this module will achieve 50W RMS into 8-ohm with 0.1% THD.

You have to provide a heavy duty heatsink rated at 1.4°C/W. Pin 10 will be the MUTE input and pin 9 provides you with a STANDBY mode. Muting ought to always take place just before standby mode is used. Connecting these pins permanently to the power supply rail (insert links) makes sure that the amplifier comes on instantly on power up. Extending the time constants R3-C6 and R4-C5 may possibly eliminate any switch-on clicks. The IC has internal thermal protection that causes the mute to cut in at 145°C and switches the amplifier into standby at 150°C. Don't operate the module without having a heatsink. The heatsink tab on the TDA7294 IC is internally connected towards the negative supply rail. When the module is mounted inside an earthed metal enclosure then the IC has to be insulated from the heatsink. If not, the negative supply rail is going to be shorted to ground.

Power Supply for 60W Class AB Audio Amplifier:

30W Class AB Power Amplifier Circuit

2011-10-22T05:12:00.000-07:00

30W Class AB power amplifier circuit diagram using power transistor. Set the above amplifier up by adjust the variable resistor R1 to maximum and R12 to zero. After this set up is done, the activate / turn on the amplifier. Adjust the R1 so that the measured output offset is between 30 and 100mV. Once set, adjust the R12 slowly to achieve a quiescent current of around 120mA. Keep checking the quiescent current as the amplifier heats up as it might change due to voltage drop changes in the output devices because of the heat. The heatsinks should be 0.6K/W or less for two amplifiers.

Power supply circuit for 30W class AB power amplifier:

45W Power Audio Amplifier Circuit with HEXFET

2011-09-25T05:46:00.000-07:00

This is 45W power audio amplifier circuit which built using HEXFET IRF9540 and IRF540. This is a ideal solution for the make a good, low cost power amplifier circuit.

Components List:

R1 = 47K ohm	C1-2-6-7 = 100nF 100V MKT	Q5-6 = IRF9540
R2-12 = 1K ohm	C3-4 = 22uF 25V	Q7-8 = IRF540
R3-4 = 3.3K ohm	C5 = 220pF styroflex	TR1 = 5K ohm trimmer multiturn
R5 = 1.2K ohm	C8-9 = 4700uF 63V	TR2 = 1K ohm trimmer multiturn
R6 = [1.2K ohm] 820 ohm *See text	C10 = 1uF 100V MKT	F1-2 = fuse 3A
R7 = 270 ohm	D1-2 = 15V 0.5W zener	J1 = 2pin connector 2.54mm step
R8 = 220 ohm	IC1 = LF411orAD711or LF351	J2 = 5pin connector 5mm step
R9 = 27K ohm	Q1 = BC550C
R10-11 = 22K ohm	Q2 = BC560C	All Resistors 1/4W 1% metal film
R13-14-15-16 = 150 ohm	Q3-4 = BC547B

The preamplifier and the driver support in a operational amplifier [IC1]. The voltage fall in resistors R5 and TR2/R6, drive the output FET's gates and is proportional with the input signal level. Transistors Q1-2 function as voltage stabilizers in the supply lines, but ensure also the essential voltage fall, because the IC1 it should not they are supplied with voltage bigger ± 18V. The consumption of all types that can be used in the place of IC1, are 2 mA, this it means voltage fall in terminal the R5 and TR2/R6 equal with the 2.4 until 2.6Volts. The current regulation it become from transistors Q3-4 in Wilson connection and the current adjustment of bias it becomes from the multiturn TR1 trimmer.

Detailed information about this 45W power audio amplifier circuit with HEXFET:
http://users.otenet.gr/~athsam/power_amplifier_45w_hexfet_eng.htm

30W Transistored Amplifier Circuit with Low Distortion Feature

2011-09-15T04:56:00.000-07:00

This is the 30W transistored amplifier circuit diagram featuring ultra low distortion. The circuit use MJE2011 and MJE2021 power transistor as the final amplification. Although this is an old circuit, but it doesn't lose the modern amplifier with power ICs and power MOSFETs.

30W transistored amplifier circuit page source: http://www.4qdtec.com/pwramp.html

Simple 2 Transistor Headphone Amplifier

2011-09-08T07:35:00.000-07:00

This is the schematic diagram of very simple headphone amplifier circuit. The circuit built using two NPN transistors. You can use transistor BC549C or other NPN transistors such as European equivalent: BC548C, BC547C, BC239, 2N5818 or 2N2222

Mono Hi-Fi Tone Control Circuit

2011-09-01T23:13:00.000-07:00

This is the mono tone control circuit. The circuit will give you high fidelity (hi-fi) output. Built the 2 similar circuit to make it stereo. Use high quality electronic parts for better audio output quality.

10 Band Equaliser Circuit

2011-08-24T23:05:00.000-07:00

This is the schematic diagram of 10 Band graphic equalizer circuit. The circuit is a mono channel, you need to build the another similar circuit to make it stereo. The power supply used for this circuit is dual polarity power supply (split power supply).

Download the full explanation about this 10 band graphic equalizer circuit and how its work here

Basic Tone Control Circuit

2011-08-18T19:03:00.000-07:00

This is the basic design diagram of tone control circuit for home audio system. The circuit can be modified refer to your needs.

Resistance value of resistor R1 is left up to the user depending on gain needs, R2 is unknown – for experiment purpose. The op-amps circuit are not critical, any standard op-amp IC could be used, for example 741, LM324, etc.

Download the PDF document of this tone control circuit here

Active Crossover Circuit based TL074

2011-08-14T20:34:00.000-07:00

This is the circuit diagram of active crossover. The crosover circuit built based TL047 and it should be placed before amplifier circuit module.

How it works..?
An audio source, like a mixer, preamp, EQ, or a recorder, is fed towards the input of the active crossover circuit. This signal is either AC or coupling, based on the setting of switch 51, the non-inverting input of buffer amplifier Ul-a, a section of a quad BIFET, low amp TL074 noise produced by Texas Instruments op. This stage has a gain of two, and its output is distributed to both a low pass filter created by R4, R5, C2, C3, and Uld op-amp, along with a high-pass filter created by R6, R7, C4 , C5, and op amp ULC. These are12 dB / octave Butterworth filters. The response of the Butterworth filter was chosen simply because it provides the most effective compromise between the damping and phase.

The values of capacitors and resistors varies based on the selected connection that your device works. The filter outputs are fed to a balancing network created by R8, R9, RIO, R14 and potentiometer RLL balance. When the potentiometer is at its center position, there is certainly a unity gain bandwidths for both high and low filters. The power supply for the electronic circuit is regulated by Crossover R12, RI3, Dl and D2, and decoupled by C6 and C7.

TDA1521 - 12W Stereo Amplifier Circuit

2011-08-06T07:58:00.000-07:00

This is the circuit diagram of 12W stereo audio power amplifier. The amplifier powered by a single power chip TDA1521. The TDA1521 contains two amplifier module. The TDA1521 has two input channel and two output channel, so, you'll only need a TDA1521 for a stereo amplifier circuit.

Source: 12W stereo amplifier

20W Power Amplifier Circuit based TDA2040

2011-07-31T14:19:00.000-07:00

The following diagram is the circuit diagram of power amplifier based power IC TDA2040. The circuit capable to deliver power audio output up to 20W with single power supply. The TDA2040 is intended for use as a class AB audio amplifier.

The TDA2040 delivers great output current and has quite low harmonic and cross-over distortion. Further the device incorporates a patented short circuit protection program comprising an arrangement for automatically limiting the dissipated power so as to keep the working point on the output transistors within their secure operating area. A thermal shut-down method is also included.

You can download the TDA2040 datasheet here

20W Power Amplifier Circuit based TDA2040

70W Stereo Audio Amplifier Circuit based STA550

2011-07-26T01:32:00.000-07:00

This is a stereo amplifier circuit diagram. The amplifier will produce stereo output channel with the power audio output can reach up to 70W for each channel. The amplifier built based great amplifier chip STA550 from STMicroelectronics. Take a note that this amplifier is a bridge amplifier, the speaker's terminal should not connected to the ground line.

Download STA550 Datasheet for your amplifier project reference.

100W Guitar Power Amplifier circuit

2011-07-22T00:33:00.000-07:00

Here the guitar power amplifier circuit which will deliver about 100W audio output. This is transistored amplifier, heatsink is a must.

The speaker and line out connections allow up to two 8 Ohm speaker cabinets (giving 4 Ohms), and a line level output for connection to a direct injection (DI) box. The level is about 1.3V (or +5dBm) at full undistorted output - change the 560 Ohm resistor to modify the level if desired.

The two 1 Ohm resistors must be rated at 10 Watts (they will still get quite hot, so mount them well away from other components). These can be mounted to the heatsink with small brackets if you want to keep them a bit cooler - remember to ensure that the heatsink can handle the extra heat input, as these two will add about 10 Watts of additional heat energy. The four 0.1 Ohm resistors should be 5W types. The amp is otherwise quite conventional. Use the parallel arrangement as shown, anything less will cause the transistors to be operated outside their safe operating area, which will result in the eventual failure of the output stage.

Make sure that the two bias diodes are mounted well clear of anything that gets hot - including the heatsink. These diodes are the two in series. All diodes should be 1N4001 (or 1N400? - anything in the 1N400x range is fine). A heatsink is not needed for any of the driver transistors.

The life of a guitar amplifier is a hard one, and I suggest that you use the largest heatsink you can afford, since it is very common to have elevated temperatures on stage (mainly due to all the lighting), and this reduces the safety margin that normally applies for domestic equipment. The heatsink should be rated at 0.5 degree C/Watt to allow for worst case long term operation at up to 40 degrees C (this is not uncommon on stage).

Make sure that the speaker connectors are isolated from the chassis, to keep the integrity of the earth isolation components in the power supply.

Guitar Pre Amplifier using TL072

2011-07-18T00:11:00.000-07:00

The following diagram is the circuit diagram of guitar pre-amplifier. The circuit built using dual op-amp circuit which is already included in IC TL072

Guitar Pre Amplifier circuit notes:

IC pinouts are industry standard for dual op-amps. Pin#4 is -ve supply, and pin#8 is +ve supply.
Diodes are 1N4148, 1N914 or similar.
Op-amp supply pins must be bypassed to earth with 100nF caps (preferably ceramic) as close as possible to the op-amp itself.
Pots should be linear for tone controls, and log for volume and master.

Guitar pre amplifier circuit source: http://projects.mestcs.com/project27b.htm

Subwoofer Driver Circuit for Stereo Car Audio System

2011-07-11T14:58:00.000-07:00

Here the schematic diagram of subwoofer driver for stereo car audio system. You may use this circuit for your home audio system.

Components Part:

R1,R4 = 1K
R2,R3,R5,R6 = 10K
R7,R8 = 100K
R9,R10,R13 = 47K
R11,R12 = 15K
R14,R15,R17 = 47K
R16 = 6K8
R18 = 1K5
P1 = 10K Log Pot
P2 = 22K Dual gang Linear Pot
D1 = LED
Q1,Q2 = BC547

C1,C2,C3,C6 = 4µ7/25V
C4,C5 = 68nF
C7 = 33nF
C8,C9 = 220µF/25V
C10 = 470nF
C11 = 100nF
C12 = 2200µF/25V
IC1 = TL072
IC2 = TDA1516BQ
SW1 = DPDT Switch
SW2 = SPST Switch (current handling min 3A)
SPKR = 4 Ohm Woofer or paralled two 8 Ohm Woofers

Circuit Notes:

The circuit connected to the output of existing amplifier. Take note that this circuit is not an amplifier, it just similar to crossover circuit.
Use heatsink to IC2 to keep the IC from overheating.

Page source of Subwoofer Driver Circuit for Stereo Car Audio System: redcircuits

5W Audio Amplifier Circuit based BD139/BD140

2011-07-09T03:40:00.000-07:00

The following is the diagram of 5W audio amplifier circuit which built using power transistor BD139 and BD140 as the final gaining process. This small amplifier can be used as general purpose amplifier such as computer amplifier, radio, mp3 player, video player, etc.

Input Stage
The input stage consists of Q1 through Q5 and 3 diodes. The differential pair is biased by Q1, R3, R4, D3, D4, and D5. The biased current is set to 1 mA. Q4 and Q5 form a current mirror as the active load for the differential pair, and the output is taken out single-endedly from the collector of Q2. The open loop gain of the input stage is more than 60dB.

Second Stage
Q8 act as a common-emitter amplifier driving the output stage. Current mirror formed by Q6 and Q7 serve both biasing current source and active load for Q8. The open loop gain of the second stage is about 40dB. Q6 and Q7 are mounted together inside the blue tube to provide thermal compensation to each other.

Output Stage
The complimentary pair BD139/140 is biased by D1, D2, and R10. Adjusting the value of R10 can yield the desired quiescent current. R13 and R14 prevent thermal run-away of the complementary pair. DC voltage at the output is always half the power supply.

Feedback
The feedback network consists of R6, R5, C3 and C4. The overall gain is about the ratio of R6 to R5. C4 provides lead compensation; C3 provides DC-blocking.

Frequency Response
The cut-off frequency is determined at the upper end by C2, R5, and C4, and at the lower end by C1, C3, and C5.

Power
Power supply voltage 12V, 5W for a 4 ohm speaker, 3W for an 8 ohm speaker.

5W audio amplifier circuit page source: http://www.zen22142.zen.co.uk/Circuits/Audio/5w12v_amp.htm

Stereo Headphone Amplifier "Studio Series"

2011-07-06T04:36:00.000-07:00

Here the diagram of stereo headphone amplifier. The circuit called Studio Series Stereo Headphone Amplifier, of course this a top rated and high performance headphone amplifier circuit.

Stereo Headphone Amplifier Main Features:

High output power (up to 200mW; into 8Ω and 32Ω)
High performance – very low noise & distortion
Drives high and low-impedance headphones
Dual headphone sockets – can drive two pairs!
Works with a preamp or any line-level audio source

Measured Performance:

Frequency response = flat from 10Hz to 20kHz (see graphs)
Rated output power = 200mW into 8Ω and 32Ω, 85mW into 600Ω
Max. output power (current or voltage limited) = 575mW into 8Ω, 700mW into 32Ω, 130mW into 600Ω
Harmonic distortion = typically .0005% (600Ω load),.001% (32Ω load) and .005% (8Ω load)
Signal-to-noise ratio (A-weighted) = -130dB (600Ω), -120dB (32Ω) and -111dB (8Ω) with respect to 100mW output power.
Channel crosstalk = better than -68dB from 20Hz-20kHz at 100mΩ output power (see graphs)
Input impedance = ~47kΩ || 47pF
Output impedance = ~5Ω

Complete electronic project, go to this page

4 Band Audio Graphic Equaliser Circuit

2011-07-01T17:52:00.000-07:00

This is the circuit of 4 band audio graphic equaliser. The equalizer will cut and boost the four range of audio frequency, that are:

Low frequency: Freq. 35-680Hz
Medium frequency: Freq. 150-3kHz
Medium/semi high frequency: Freq. 450-8.5kHz
High audio frequency: Freq. 750-15kHz

Circuit note: Use regulated power supply, metalfilm resistor, MKM nonpolar capacitor and tantalum bipolar capacitor for best audio quality result.

This circuit is available in PDFdocument. Download 4 Band Equalizer circuit from the following link:
Download Link

1KHZ Sine Wave Generator Circuit

2011-06-28T06:53:00.000-07:00

This circuit generates a great 1KHz sine wave adopting the inverted Wien bridge configuration (C1-R3 & C2-R4). It features a variable output, low distortion and low output impedance in order to obtain excellent overload capability. A small filament bulb ensures a stable long term output amplitude waveform.

Parts List:
R1 = 5K6 - 1/4W
R2 = 1K8 - 1/4W
R3,R4 = 15K - 1/4W
R5 = 500R - 1/2W Trimmer Cermet
R6 = 330R - 1/4W
R7 = 470R - Linear Potentiometer
C1,C2 = 10nF
C3 = 100µF/25V
C4 = 470nF
Q1,Q2 = BC238
LP1 = 12V 40mA Filament Lamp Bulb (See Notes)
J1 = Phono chassis Socket
SW1 = SPST Slider Switch
B1 = 9V PP3

Circuit Notes:

High gain transistors are preferred for better performance.
The bulb must be a low current type (12V 40-50mA or 6V 50mA) in order to obtain excellent long term stability and low distortion.
Using a bulb differing from specifications may require a change of R6 value to 220 or 150 Ohms to ensure proper circuit's oscillation.
Distortion @ 1V RMS output is 0.15% using a 12V 40mA bulb, raising to 0.5% with a 12V 100mA one.
Set R5 to read 1V RMS on an Audio Millivoltmeter connected to the output with R7 rotated fully clockwise, or to view a sinewave of 2.828V Peak-to-Peak amplitude on the oscilloscope.
With C1, C2 = 100nF the frequency generated is 100Hz and with C1, C2 = 1nF frequency is 10KHz but R5 requires adjustment.

1KHZ sine wave generator circuit source: http://www.redcircuits.com/Page13.htm

3W- 5W Audio Amplifier Circuit

2011-06-24T20:34:00.000-07:00

The following diagram is the class-a audio amplifier circuit. The circuit capable to deliver about 3W up to 5W power audio output.

Schematic diagram

Parts List:

R1 = 100K - 1/4W
R2 = 12K - 1/4W
R3 = 47K - 1/4W
R4 = 8K2 - 1/4W
R5 = 1K5 - 1/4W
R6 = 2K7 - 1/4W
R7,R9 = 100R - 1/4W
R8 = 560R - 1/2W
R10 = 1R - 1/2W

P1 = 47K Log. Potentiometer
C1,C2 = 10µF/63V
C3 = 47µF/25V
C4 = 100µF/35V
C5 = 150nF
C6,C7 = 220µF/25V
C8 = 1000µF/25V
Q1 = BC560C
Q2,Q3 = BD439

Circuit Notes:

Total electric current drawing of the circuit, recommended measured by inserting the probes of an multimeter across the positive output with the power supply and also the positive rail input with the amplifier, should be 700mA. Adjust R8 to obtain this value if needed.
Q2 and Q3 must be mounted on a finned heatsink of 120x50x25mm. minimum dimensions.
If needed, R2 could be modified to get 13V across C8 positive lead and negative ground.
Add R5 and C5 if the bass-boost facility is needed.

3W- 5W Audio Amplifier circuit source: redcircuits.com

Mic Audio Mixer Circuit

2011-06-20T18:48:00.000-07:00

The following design is the circuit diagram of microphone audio mixer with 3 input channels. It use 741 op-amp to amplify the input signal. This circuit can be used for dynamic microphone.

Components Part:
R1, R2, R3 = 1K
R4, R5, R6 = 10K Logarithmic Pot
R7 = 1M
R8, R10 = 10K
R9, R11 = 100K Linear Potensiometer
C1, C2, C5, C6 = 100nF
C3, C4 = 22nF
U1, U2 = IC 741 Op-Amp
J1, J2, J3 = Input Mic Jacks
MISC = Board, Wire, Knobs, IC Sockets

Mic Audio Mixer Circuit Notes:

R1-R3 are volume level control on each input. R9 and R11 will control bass and treble for all input.
The circuit only need low current to run, two 9V batteries which connected in parallel can be used for a power supply.
The placement of the mixer in a metal case and connected the ground to the case will cut down on noise.

Circuit Source: aaroncake.net

18W Audio Amplifier Circuit based TIP41A/TIP42A

2011-06-16T23:28:00.000-07:00

This is an amplifier circuit capable to deliver 18 Watt RMS into 8 Ohm speaker. You do not need to build a preamplifier because the pre-amp already included in the this circuit based IC TLE2141C which is a low noise, high voltage, high slew-rate Op-amp.

Amplifier parts list:
P1 = 22K Log. Potentiometer (Dual-gang for stereo)
R1 = 1K
R2 = 4K7
R3 = 100R
R4 = 4K7
R5 = 82K
R6 = 10R 1/2 watt
R7 = R22 4W Resistor (wirewound)
R8 = 1K 1/2W Trimmer Cermet (optional)
C1 = 470nF
C2,C5 = 100µF/3V Tantalum
C3,C4 = 470µF/25V
C6 = 100nF
D1 = 1N4148
IC1 = TLE2141C
Q1 = BC182
Q2 = BC212
Q3 = TIP42A
Q4 = TIP41A

Power supply parts list
R9 = 2K2 1/4W Resistor
C7,C8 = 4700µF 25V Electrolytic Capacitors
D2 = 100V 4A Diode bridge
D3 = 5mm. Red LED
T1 = 220V Primary, 15 + 15V Secondary, 50VA Mains transformer

18W Audio Amplifier Circuit Notes:

Can be directly connected to CD players, tuners and tape recorders.
Do not exceed 23 + 23V supply.
Q3 and Q4 must be mounted on heatsink.
D1 must be in thermal contact with Q1.
Quiescent current (best measured with an multimeter in series with Q3 Emitter) is not critical.
Adjust R3 to read a current between 20 to 30 mA with no input signal.
To facilitate quiescent current setting add R8 (optional).
A correct grounding is very important to eliminate hum and ground loops. Connect to the same point the ground sides of J1, P1, C2, C3 & C4. Connect C6 to the output ground.
Then connect separately the input and output grounds to the power supply ground.

Source: redcircuits.com

Audio Mixer based JFET 2N3819

2011-06-15T02:08:00.000-07:00

This is the audio mixer circuit based Junction FET (JFET) of 2N3819.

Audio Mixer based JFET 2N3819 circuit diagram:

Audio Mixer based JFET 2N3819 Parts List:
R1, R3 = 10K Pot
R2, R4 = 100K 1/4 W Resistor
R5 = 6.8K 1/4 W Resistor
C1, C2, C3 = 0.1uF Capacitor
Q1 = 2N3819 Junction FET

Circuit Notes:

As numerous or as few channels as are needed may be added to the mixer. Do this by just duplicating the input "sections" that are shown on the schematic design.
A shielded case is perhaps necessary to minimize hum and support to avoid oscillations.
The Audio Mixer circuit could be powered by a single 9 volt battery.

Original circuit page: go to this page

10W Audio Amplifier Circuit

2011-06-14T00:02:00.000-07:00

This is 10W mini audio amplifier circuit based TDA2003. The voltage supply is 9V, you may increase the voltage for higher gain (24V VCC max).

Parts List:
R1 : 2.2 Ohm
R2 : 220 Ohm
R3 : N/A
R4 : 10 KOhm pontesiometer
C1 : 2200 uF / 25V
C2 : 470 uF / 16V
C3 : 470 nF / 63V
C4 : 100 nF
C5 : N/A
C6 : N/A
IC1 : TDA 2003

5-Band Equaliser Circuit

2011-06-09T05:40:00.000-07:00

Audio Circuit » Equaliser » 5-Band Equaliser Circuit

Above circuit is a 5-Band graphic equaliser circuit from Electronic For You Magazine, published May 2007. This equaliser uses low-cost op-amps NE5532 or LM833. Those ICs are good-quality op-amps powered by a single voltage supply are readily available in the market.

This 5-Band equaliser circuit is powered by a 12V DC regulated power supply. A well-regulated power supply using 7812 is recommended.

Download 5-Band Equaliser Circuit document from Electronic For You Magazine:
» Download Link

68W Power Amplifier Circuit based LM3886

2011-06-05T15:16:00.000-07:00

The following diagram is a 68W Power Amplifier Circuit diagram based on famous amplifier chip LM3886.

Components List:

R1 = 10K Ohms
R2 = 10 Ohms 2W see text
R3 = 10 Ohms
R4 = 47K Ohms
R5 = 220K Ohms
R6 = 10K Ohms
R7 = 100K Ohms
L1 0,7uH
IC1 LM3886

C1 = 100NF
C2 = 100NF
C3 = 100NF
C4 = 100UF
C5 = 100UF
C6 = 4,7UF
C7 = 100UF
C8 = 1UF

Amplifier should be fed by source symmetrical good filtered of + 34 and – 34 volts. R2 and L1 is a resistor of 10 ohms / 2watt coiled with 10 to 12 you exhale of enameled thread AWG 20. The circuit integrated lm3886 is a component easy of being found at the electronics stores, for that he is used in several projects of potency audio, some exist circuits with linked lm3886 in bridges for potencies of up to 150 watts. For most information on the assembly of that circuit, please read the datasheet of the LM3886. With the information of the leaf of data you can adapt the circuit with LM3886 your needs.

Circuit Source: http://electronics-diy.com/68-watts-lm3886-power-amplifier.php

100W Power Amplifier

2011-06-01T16:03:00.000-07:00

It is cheap and easy to make power amplifier which will deliver 100W - 150W power audio output. Great project choice for your Do-It Yourself amplifier project.

Circuit Notes:

This amplifier circuit requires dual polarity power supply. You may use this dual polarity power supply circuit
Use heatsink aluminium on the power transistor to prevent over heating.
The 45V power supply is the maximum, use 32V center tapped transformer.

Mini Mic Pre-Amplifier Circuit based IC LM358

2011-05-27T16:22:00.000-07:00

The following diagram is a easy to build, simple and low cost mic pre-amp circuit which build using op-amp chip of LM358.

Component Parts List:
R1, R3, R4 = 10K
R2 = 1K
R5 = 100K-1M Potensiometer
C1 = 0.1uF
C2 = 4.7uF/16V
IC1 = LM358 dual op-amplifier
Mic = Electret Microphone

Notes:

Vary the variable resistor of R5 to adjust the gain of op-amplifier IC LM358.
The LM358 has two op-amp module, you may build stereo audio pre-amplifier using single LM358.

Need a reference for LM358? Then download LM358 datasheet

Audio Booster Circuit

2011-05-21T20:43:00.000-07:00

The following circuit has a maximum gain of around 22 dB (voltage gain). The frequency response of the amplifier is determined mostly by the value of just a couple of components, primarily C1 and R1. The values of the circuit diagram present a response of ±3.0 dB from about 120 Hz to higher than 20,000 Hz.In fact, the frequency response is ruler flat starting from about 170 Hz to more than 20,000 Hz; it's the low end that deviates from a flat frequency response.

The low end's roll-off is primarily a function of capacitor C1(since RI's resistive value is fixed). If C1's value is replaced to 0.1 pF, the low end's comer frequency-the frequency at which the low-end roll-off starts-is reduced to about 70 Hz. In the event you want an even deeper low-end roll-off, change C1 to a 1.0 pF capacitor; if it is an electrolytic type, make particular that it is installed into the circuit with the proper polarity, using the positive terminal connected to Q1's base terminal.

Sample circuit design with component value:

Transistored 15W Amplifier circuit

2011-05-13T15:16:00.000-07:00

The following diagram is a 15W power amplifier circuit which use power transistors as the main components. Make sure you are using coolrib/heatsink... :)

This amplifier uses a dual 20 Volt power supply and delivers 15 watts RMS into an 8 ohm load. Q1 operates in common emitter, the input signal being passed to the bias chain consisting of Q8, Q9, D6, D13 and D14. Q8 and Q9 provide a constant current through the bias chain to minimize distortion, the output stage formed by a discrete darlington pair (Q2,Q4) and (Q7,Q11). The last two transistors are power Transitors, specifically the 2N3055 and MJ2955. The 7.02K resistor, R16 was made using a series combination of a 4.7K, 680 Ohms, and two 820 Ohms. The 1.1K resistor, R3 was made using a 100 Ohms and a 1K resistor. You can use this circuit with any, MP3 player, walkman or CD player since it is designed to take a standard 500mv RMS signal.

Circuit design by Sergio Garcia de Alba Garcin
Source: http://www.zen22142.zen.co.uk/Circuits/Audio/amp15.htm

Audio Amplifier 4 transistors

2011-04-23T08:39:00.000-07:00

A very simple and easy to construct class AB audio amplifier by using 4 transistors is provided right here. In class AB operation every output device performs more than half of the input signal cycle. As much as 78% efficiency is possible with class AB types and cross over distortion is minimized. The circuit shown right here is suitable for small radio receivers, audio players, intercom, phone and so on.

Transistor Q1 with its connected components is wired as a pre-amplifier place. The audio input is coupled towards the base of Q1 through resistor R1 and capacitor C1. Resistor R3 provides collector to base bias for Q1 and C3 is an AC by pass capacitor for the collector resistor R4. Collector to base biasing is really a good method of biasing for circuits like this because it provides enough negative feedback, prevents thermal runway and stabilizes the operating point. The second stage will be the driver stage for the push pull pair. Q2 with its connected parts perform this job. This stage is also collector to base biased, and its input is coupled to the output from the pre-amplifier stage using capacitor C2. Resistor R8 limits the collector present of Q2.The third stage will be the class AB push pull section comprising of transistors Q3 and Q4. Diodes D1 and D2 offers the bias voltage for the push pull stage. The output from the amplifier is coupled towards the loud speaker via the capacitor C4. C5 and C6 are voltage source / power supply filter capacitors.

Circuit Notes:

K1 can be an 8 ohm/5Wof loud speaker.
The circuit may be assembled on a vero board.
C6 should be grounded close to towards the Q1 and C5 must be grounded close to towards the loud speaker ground. This reduces noise.
Use 5V DC for powering the circuit.

STK4231II, Stereo Amplifier 2x100 Watts

2011-04-18T22:40:00.000-07:00

Do you want to make a simple amplifier, but has ability to deliver very high audio power output? If true, then the circuit is the answer for you. This circuit built using an IC for each channel, so you need two power ICs of STK4231II to make a stereo amplifier circuit.

Each IC will deliver audio power output about 100W, so we can call this circuit as a 2x90W stereo power amplifier. This circuit must be supplied by using a dual polarity power supply and you have to install the heatsink on each IC to avoid overheating.

Download STK4231II datasheet:
Download Link

10W Amplifier Circuit Based TDA1910

2011-04-08T19:58:00.000-07:00

Here the diagram of 10W Amplifier circuit based TDA1910

You need the TDA1910 datasheet? Download here

1W Mini Amplifier Circuit based TDA7052

2011-03-23T05:57:00.000-07:00

This is a mini audio amplifier based IC TDA7052. This amplifier is a mono amplifier with single input and single output. You need to build two circuits for stereo amplifier.

Parts List:

R1 : 1K ohm resistor
R2 : 10K ohm log potentiometer
C1 : 2.2uF/16V electrolytic capacitor
C2 : 100nF ceramic/mono
C3 : 100uF electrolytic
TDA7052 Integrated Circuit
8 pin IC socket

Download area:

Circuit tutorial
TDA7052 datasheet

Low Cost Mixer Circuit

2011-02-11T22:47:00.000-08:00

The following circuit is an easy, simple and cheap mixer circuit.

A simple mixer circuit suitable for mixing microphones or effects outputs. The overall gain from input to output is one if the pot related towards the input is full up. You'll be able to generate this a net gain of ten (or any other reasonable gain) by lowering the input resistor towards the second op amp. 10K in this position provides a gain of 10db, or 20db. If you are mixing effects outputs which have an output level control built into them, it is possible to dispense using the input level controls, or make some have level controls, some not. Audio taper pots are most likely better, but linear will be work.

For the op amps, pick a JFET input dual or singles, such as from the National Semi LF3xx series, or something such as the TL072 or TL082.

Download this Low Cost Mixer Circuit in PDF file:
Download Link

Stereo Tone Control Circuit with Transistor

2011-02-09T00:34:00.000-08:00

Above diagram is the circuit diagram of stereo tone control which also available to buy in kit, you could possibly look for the kit at electronic part store close to your location. The tone control require 12v of power supply to work.

The circuit build based on ordinary tone control circuit, by using two transistors FCS9014 in each channel, so there are actually four transistors in this stereo audio tone control. Take a note that you should connect this circuit before the amplifier circuit. The output of tone control need to be connected towards the input of the amplifier. Any small signal NPN transistor for example BC547B, 2N3904, C828, or C945 might be applied to replace FCS9014 transistor.

Stereo Tone Control Circuit Based LM1036N

2011-01-24T13:45:00.000-08:00

The following circuit is a Stereo Tone Control Circuit which build based LM1036N.

The LM1036 works as a DC controlled tone (bass/treble), volume and balance circuit for stereo audio purposes in car radio, TV and audio systems. An extra control input will allow loudness compensation to be simply effected. Four control inputs provide control of the bass, treble, balance and volume capabilities through application of DC voltages from a remote control system or, additionally, from four potentiometers that might be biased from a zener regulated supply given on the circuit. Each tone response is defined by a single capacitor selected to give the desired characteristic.

Circuit Features:
Large volume control range, 75 dB typical
Wide power supply voltage range of 9V to 16V
Channel separation, 75 dB typical
Tone control, 15 dB typical
High signal to noise, 80 dB typical for an input level of 0.3 Vrms
Low distortion, 0.06% typical for an input level of 0.3 Vrms
Few outside parts needed

Note: Vcc can be anything between 9V to 16V and also the output capacitors are 10uF/25V electrolytic.

Angry Beard III Guitar Effect Circuit

2011-01-06T22:42:00.000-08:00

The OP-AMP can be any single small noise op-amp, the original NE5534 is used. The 2N44 is probably to get replaced by other PNP germanium transistors without having much change in sound. The switching factor has been omitted from this diagram, but you almost certainly wish to add a bypass of some varieties to this impact.

This emphasis switch chooses a tone taste, this may very well be expanded to incorporate a wider scale of frequencies, but too tiny a capacitor value could lead to oscillation.

All tame a company internal confirmation of this impact has long been omitted, nevertheless it can be easy to add. This could be noisy, according to the platform, to ensure the capacitor with value 10-15pF may very well be positioned inside a cycle of OP-amp if you're apprehensive an excessive amount of squeaking.

Download Angry Beard III Guitar Effect circuit diagram and PCB layout Right here

This Angry Beard III Guitar Effect designed by Jamie Helman

STK-0060II, 60W AF Amplifier

2010-12-18T19:53:00.000-08:00

The following diagram is the circuit diagram of 60W AF Amplifier based on single IC STK-0060II. The IC is a high power amplifier manufactured by Sanyo.

STK-0060II Features:
STK STK-0060II is equipped with the following features:

IMST system
Dual power supply
Darlington pure complementary circuit
Metal substrate used IMST^c makes good thermal stability

Download STK-0060II datasheet include the application circuit schematic:
Download Link

TDA7294: 50W Power Audio Amplifier

2010-12-12T02:40:00.000-08:00

Parts list:

R1 = 150R
R2, R3, R5 = 10K
R4 = 680R
R6 = 22K
IC1 = TDA 7294
Heatsink

C1 = 1u5F or 1u
C2 = 2n7F
C3, C6 = 22uF 63V
C4, C5 = 10uF 63V
C7, C9 = 2200uF 50V
C8, C10 = 100nF

This is a great audio amplifier circuit is based on the power IC TDA7294. TDA7294 is intended for use as class AB amplifier in hi-fi audio applications. It's very quiet of noise and distortion, has wide bandwidth and high output current capability, so that we can provide high power at both 4Ω and 8Ω loads. TDA7294 has both short-circuit and thermal protection, so it is strong enough.

With the addition of a handful of parts and a suitable power supply, this module will deliver over 50W RMS into 4 or 8 ohms with < 0.1% Total Harmonic Distortion (THD) and < 0.1% Intermodulation Distortion (IMD). A similar circuit was published in Elektor magazine, 11/96.

It is also suitable as a replacement power amplifier stage, or upgrade for many existing amplifiers of between 30W-50W, provided they have a suitable dual supply, and most do.

Download the explanation of TDA7294 amplifier circuit include the diagram in pdf format HERE

325mW Mini Amplifier Circuit based LM386

2010-12-02T12:52:00.001-08:00

The following schematic diagram is a mini amplifier circuit based on LM386 with a voltage gain of 200 and power output of 325mW that can be used as a bench amplifier, signal tracer or used to amplify the output from personal computers, MP3 players, MP4 Players, iPods, personal radios or others electronic device with audio support.

The IC operates from 4 to 12 V DC, 12 V being the recommended maximum. The internal input impedance of the amplifier is about 50K. This is deflected by a regular 22k potentiometer, input impedance, so this circuit will be less than 15k. The input is DC coupled so be careful not to extend the DC circuit precedent. Otherwise, the speaker may be damaged. A coupling capacitor may included in series with the 22k control to prevent this from happening.

2x3W Stereo Amplifier based on BA5406

2010-11-22T21:30:00.000-08:00

The following diagram is the schematic diagram of stereo audio amplifier which able to deliver the power output up 3 W on each channel. The amplifier circuit powered with single power amplifier chip BA5406.

Component part list:
R3, R4 = 2R2 ohm
R1, R2 = 120 ohm
C1, C2, C11, C12 = 220nF
C3, C4, C5, C6, C7, C8 = 47uF/16V
C9, C10 = 470uF/16V
IC = BA5406

The BA5406 is a dual-OTL monolithic power IC with two high-output, low-frequency power amplifiers. With a 12V power supply, it has a rated output of 5W x 2 into a 3W load, and with a 9V power supply, it has a rated output of 2.8W x 2 into a 3W load.

The BA5406 has good low-voltage characteristics, and the “pop” sound when power is applied is small. It generates little radio-band noise, and is ideal for use in stereo radio cassette players.

Download 2x3W Audio Amplifier with IC BA5406 in PDF version
Download BA5406 datasheet

80W Power Amplifier based LM12

2010-11-07T19:04:00.000-08:00

This is a very simple amplifier circuit based LM12. Although with a very simple design of schematic diagram, but this circuit can provide output power up to 80W. To get stereo output, make two pieces the same circuit and connect it to each output of the stereo tone control / pre-amp / mixer / equalizer or radio/mp3 player / ipad / dvd player / tv output.

Circuit diagram:

PCB layout:

LM12 Features:
There are important features included on LM12:

Input protection
Controlled turn on
Thermal limiting
Overvoltage shutdown
Output-current limiting
Dynamic safe-area protection

You may download the LM12 datasheet HERE

2000W Power Amplifier circuit

2010-10-31T03:01:00.000-07:00

Here the circuit diagram of 2000 watt power audio amplifier. This circuit should be for advanced electronic hobbyst.

The circuit is hard enough to built, I think you need electronic cad software like eagle, diptrace or proteus to rebuild the schematic and create PCB design from it.

http://wiringschematics.net/2000w-power-amplifier-schematic-diagram.html

50W Power Amplifier Circuit

2010-10-13T17:46:00.001-07:00

The following diagram is a 50W power amplifier circuit diagram based on a pair of power transistors MJ2955 and 2N3055. The transistors are usually used for OCL amplifier, the output audio quality is very good, you should buy the transistors which have good quality . Using heatsink on the transistors is a must.

Here the Schematic diagram:

PCB layout:

This amplifier require dual output power supply (+, ground and -). Use this power supply circuit:

For maximum performance, use 3-5 Ampere transformet with 24V secondary output.
You may use 5A Diode bridge or 4 pieces of single 5A diode.

200W RMS Power Amplifier circuit

2010-10-08T23:18:00.000-07:00

Above circuit is an 200W RMS power audio amplifier which containing many transistors to gain the high power output. The circuit is quite simple but will give you high quality audio output.
Download large schematic diagram in PDF format HERE

800W Power Amplifier Circuit

2010-09-28T21:23:00.000-07:00

The following diagram is a 800W power amplifier circuit which use so many MOSFET to gaining the high power output.

This amplifier can be used for practically any application that requires high power, low noise, distortion and excellent sound. Examples would be Sub-woofer amp, FOH stage amplifier, One channel of a very high-powered surround sound amplifier etc.

Visit the 800W audio amplifier circuit with MOSFET for detailed document.

TDA7240A, 20W Car Amplifier Circuit

2010-08-22T21:45:00.000-07:00

This is TDA7240A based bridge amplifier circuit for car audio system. You may use this circuit for home audio system. The output power will be up to 20W.

Schematic Diagram:

PCB Layout:

Note: The schematic and PCB layout have taken from datasheet. Please download the datasheet HERE

140W Power Amplifier circuit based on STA5100

2010-08-08T16:40:00.000-07:00

The following circuit is 140W power audio amplifier, built based on single power IC STA5100. This is a mono channel amplifier, build the same circuit will make it stereo. 140W output is very high value for home audio system. It needs high power of supply to make the circuit works in maximum performance.

Circuit diagram:

The circuit contains all the blocks to build a mono amplifier. It is based on the Output Bridge Power Amplifier, and its protection circuit. Moreover, the compression function and a signal rectifier are added to complete the circuit.

The operation modes are driven by The Turn-on/off sequence block. In fact the IC can be set in three states by the Stby/mute pin:

Standby ( Vpin <> 4V).

In the Standby mode all the circuits involved in the signal path are in off condition, instead in Mute mode the circuits are biased but the Speakers Outputs are forced to ground potential.

Download the STA5100 datasheet for complete reference about STA5100.

60W Audio Amplifier with TDA2052

2010-07-20T03:37:00.000-07:00

This is a schematic diagram of 60 Watt audio amplifier based on TDA2052:

The TDA2052 is a monolithic integrated circuit, intended for use as audio class AB amplifier in TV or Hi-Fi field application. With low distortion feature, the TDA2052 should be good enough for middle audio system.

Continue reading..? Visit this 60W audio amplifier page

Low Pass Filter circuit

2010-06-15T08:51:00.000-07:00

This is a Low band pass filter circuit especially designed for subwoofer loudspeaker. There are two input channels from stereo audio system, and the output was one output channel which connected to one subwoofer. Just like active speaker for computer.

Schematic Diagram:

PCB Layout:

Component Placement:

Source:
http://www.high-voltage-lab.com/7/low-pass-filter-subwoofer

Visit the source page for detailed information about this low band pass circuit.

32W Audio Amplifier Circuit based on TDA2050

2010-05-24T02:48:00.000-07:00

Below is an amplifier circuit based power IC TDA2050. This circuit is able to give voice to the single output of 32W with good audio quality. IC2050 can be found on the market with ease, and sold at low prices.

32W Amplifier Schematic diagram:

32W Amplifier PCB Design:

Notes:

Use heatsinks to absorb heat in the IC
Use recommended voltage value for maximum performance, see the datasheet.

Download TDA2050 datasheet for your electronics project reference.

10W Transistored Audio Amplifier circuit

2010-05-13T02:59:00.000-07:00

Here's a circuit diagram from 10W audio amplifier. With a pair of transistors TIP41A/TIP42A main components, this amplifier audio system good enough for you because it can produce good bass with the lift curve reaches a maximum of +16.4 dB @ 50Hz.

Component Parts:

P1 22K Log.Potentiometer
P2 100K Log.Potentiometer
R1 820R
R2,R4,R8 4K7
R3 500R Trimpot
R5 82K
R6,R7 47K
R9 10R
R10 R22 4W Resistor (wirewound)
D1 1N4148
IC1 NE5532

C1,C8 470nF 63V
C2,C5 100uF 25V
C3,C4 470uF 25V
C6 47pF 63V
C7 10nF 63V
C9 100nF 63V
Q1 BC547B NPN Transistor
Q2 BC557B PNP Transistor
Q3 TIP42A PNP Transistor
Q4 TIP41A NPN Transistor
J1 RCA audio input socket

Power supply parts:
R11 1K5
C10,C11 4700uF/25V
D2 100V 4A Diode bridge
D3 5mm. Red LED
T1 220V Primary, 12 + 12V Secondary 24-30VA Mains transformer
PL1 Male Mains plug
SW1 SPST Mains switch

Notes:

Can be directly connected to CD players, tuners and tape recorders.
Schematic shows left channel only, but C3, C4, IC1 and the power supply are common to both channels.
Numbers in parentheses show IC1 right channel pin connections.
A log type for P2 ensures a more linear regulation of bass-boost.
Don't exceed 18 + 18V supply.
Q3 and Q4 must be mounted on heatsink.
D1 must be in thermal contact with Q1.
Quiescent current (best measured with an Avo-meter in series with Q3 Emitter) is not critical.
Set the volume control to the minimum and R3 to its minimum resistance.
Power-on the circuit and adjust R3 to read a current drawing of about 20 to 25mA.
Wait about 15 minutes, watch if the current is varying and readjust if necessary.
A correct grounding is very important to eliminate hum and ground loops. Connect in the same point the ground sides of J1, P1, C2, C3 &C4. Connect C9 at the output ground.
Then connect separately the input and output grounds at the power supply ground.

Source: redcircuits.com

35W Audio Amplifier Circuit based on STK082

2010-04-28T08:17:00.000-07:00

This is a very simple amplifier, very easy to build and produce sound output with a fairly large power of 35 watts. This circuit used power chip STK082 as its main component.

You need a split power supply to make this circuit work. And to avoid excessive heat, you should use a heatsink on the power IC

Download the STK082 datasheet

5.8W Amplifier Circuit based IC KA2211

2010-04-01T16:25:00.000-07:00

Here the another simple dual power amplifier circuit based on single samsung chip KA2211. This power IC only supported with a few external passive component to work and able to deliver 5.8W on each output.

KA2211 is a dual audio power amplifier for consumer application. It is designed for high power, low dissipation dan low noise. Is also contains various of protectors and suitable for car audio power amplifier with high performance.

Download IC KA2211 datasheet for your project reference

Headphone Amplifier with LM833

2010-03-28T02:09:00.000-07:00

This is a headphone amplifier circuit based on IC LM833 or NE5532 supporter with 4 transistors (one channel). The input can be directly connected to audio devices such as MP3/MP4 player, CD/DVD plater, radio or computer.


Amplifier part list:
P1 __________ 22K Log.Potentiometer (Dual-gang for stereo)
R1 __________ 560R
R2,R3 _______ 10K
R4 __________ 12K
R5,R6 _______ 2R2
R7 __________ 22R
C1 __________ 1uF/63V
C2,C3,C4 ____ 100uF/25V
C5 __________ 22pF/63V
C6 __________ 22uF/25V
IC1 _________ LM833 or NE5532
Q1,Q3 _______ BC337 45V 800mA NPN Transistors
Q2,Q4 _______ BC327 45V 800mA PNP Transistors
J1 __________ RCA audio input socket

Power supply part list:
R7 __________ 2K2
C7,C8 _______ 2200uF/25V
D1 __________ 100V 1A Diode bridge
D2 __________ 5mm. or 3mm. Red LED
IC2 _________ 7815 15V 1A Positive voltage regulator IC
IC3 _________ 7915 15V 1A Negative voltage regulator IC
T1 __________ 220V Primary, 15 + 15V Secondary 5VA Mains transformer
PL1 _________ Male Mains plug
SW1 _________ SPST Mains switch

Technical data:

Output voltage: Well above 5V RMS on all loads
Sensitivity: 250mV input for 5V RMS output
Frequency response: Flat from 30Hz to 20KHz
Total harmonic distortion @ 1KHz & 10KHz: Below 0.005% on 32 Ohms load and up to 4V RMS output (typical 0.003%)
Total harmonic distortion @ 1KHz & 10KHz: Below 0.005% on 100 to 2000 Ohms load and up to 5V RMS output (typical 0.003%)

7W Stereo Audio Amplifier based LM4756

2010-03-17T15:36:00.000-07:00

Here the another audio amplifier circuit. This is a dual output (stereo) audio amplifier based on single Power IC LM4756

Circuit Diagram:

PCB layout:

Download this LM4756 Datasheet

15W AF Amplifier with STK075

2010-02-27T18:10:00.000-08:00

Here the 15W amplifier based on STK075. This amplifier will deliver 12W output power.

Recommended power supply voltage for this circuit is 20VDC

Download STK075 Datasheet

TDA1514A - 50W Power Amplifier Circuit

2010-02-18T03:21:00.000-08:00

The TDA1514A is a power amplifier chip that will gain up to 50W high fidelity output power.

This hi-fi power amplifier circuit can be used as a building block in radio, tv and other audio applications. The high performance of the IC meets the requirements of digital sources (e.g. Compact Disc equipment).

The circuit is totally protected, the two output transistors both having thermal and SOAR protection. The circuit also has a mute function that can be arranged for a period after power-on with a delay time fixed by external components.

The device is intended for symmetrical power supplies but an asymmetrical supply may also be used. Datasheet of TDA1514A HERE

Simple Audio Pre-Amp circuit

2010-02-02T20:03:00.000-08:00

Designed based on single Transistor 2N3904, this circuit will provide good gain for weak audio signals such as electret microphone. Easy to build and really simple for pre-amp circuit.

Stereo Amplifier based TDA2005

2010-01-14T15:51:00.000-08:00

Simple, inexpensive and powerfull stereo power amplifier for your practice. The output audio performance is good enough for cheap amplifier :)

Component list:

R1, R9 ________ 1K ohm
R2 ____________ 120K ohm
R3, R4 ________ 1K2 ohm
R5, R6 ________ 33 ohm
R7, R8 ________ 1 ohm

IC ____________ TDA2005
Pot ___________ 10K ohm stereo

C1 C2 __________ 2u2/50V
C3 _____________ 10uF/25V
C5, C6, C8 _____ 100uF/25V
C7, C9 _________ 220uF/25V
C12, C13 _______ 2200uF/16V
C4 _____________ 100nF
C10, C11 _______ 100nF

This is a class AB stereo audio power amplifier designed for quality hi-fi applications using a power IC TDA2005. It is easy to construct and has a minimum of external components. The module has output current protection and thermal protection. This is the data book circuit which produces an excellent sound. The supply voltage required for this kit is 8 – 18V DC at 1 to 2 Amps.

Vieh more about Stereo amplifier circuit with TDA2005

25W Amplifier based LM1875

2010-01-01T19:06:00.000-08:00

This is the schematic diagram of 25W Amplifier based LM1875. This is an high quality audio power amplifier that you could build this circuit easily.

Component part list

R1 _____________ 1K
R2 _____________ 1M
R3 _____________ 22K
R4 _____________ 10K
R5 _____________ 180K
R6 _____________ 1R

IC1 ____________ LM1875

C1 _____________ 1uF 50V
C2,6 ___________ 100nF
C3 _____________ 22uF 63V
C4 _____________ 0.22uF
C7,5 ___________ 220uF 50V 

Miscellaneous:
Fuse holder & cover
2 amp fuses

View more explanation of this 25W audio amplifier

One Transistor Audio Booster circuit

2009-12-25T03:14:00.000-08:00

Here the schematic diagram of Audio Booster circuit based on single Transistor 2N3392

Component Parts:


R1____________47K
R2____________470K
R3____________10K
R4____________560 Ohm
R5____________100K Linear pot+switch
R6____________270 ohm


Q1____________2N3392
LED1____________red LED
C1____________05-.1μF Ceramic
C2____________0.1μF Ceramic
C3____________33μF/25V

The 2N3392 transistor is a low-noise type in a TO-92 housing and can be replaced by a NTE199 or ECG199. Potentiometer R5 of 100K is a linear type with an on/off switch attached.

The value of C1 may need to be between 0.05μF and 0.1μF (47nF/100nF). Experiment with the value for best performance.

2×22W Stereo Power Amplifier based TDA1553CQ

2009-12-14T16:06:00.000-08:00

This is 22W stereo power amplifier with single power IC TDA1553Q. With single power IC, this circuit could handle two audio channel. This amplifier will be great for your car audio system.

The TDA1553CQ contains two identical amplifiers with differential input stages and can be used for bridge applications. The gain of each amplifier is fixed at 26 dB.

Vinyl Pre-Amplifier circuit

2009-11-28T19:12:00.000-08:00

This is Vinyl Pre-amplifier circuit. This circuit will make your audio system have a great audio performance.

Detail explanation about this vinyl, visit this page.

10 LEDs Audio VU Meter circuit with LM3915

2009-10-27T18:03:00.000-07:00

This is very nice VU meter circuit for your own audio system project.

Build based IC LM3915, this circuit will indicate the power audio level of your audio system. This circuit is very simple, inexpensive and easy to build.

Visit this page for complete explanation. Follow the instruction and use the proper power supply for this circuit.

Power Amplifier with Power IC STK40xx series

2009-10-16T22:04:00.000-07:00

Here the famous power audio amplifier based power IC STK40xx series. This is very simple circuit because only need several external component to support the power IC. You need heatsink to prevent overheating on the IC and proper power supply to make the best result.

Schematic Diagram:

Component Part list

R1-4 =1Kohm
R2= 33Kohm
R3-8=100ohm
R5= 0.22ohm 5W
R6=10ohm 2W
R7= 6,8ohm 2W
R9=12Kohm
R10=10Kohm
R11= 680ohm
C1=560 pF 100V ceramic or mylar
C2-7 =1 uF 63V MKT

C3-12 =220 uF 63V
C4-5-10 =100 pF
C6-9 =47uF 63V
C8 =100 nF 100V MKT
C11 =1 nF 100V MKT
C13 =100 uF 25V
C14=10pF 100V ceramic or mylar
L1 =3μH [15 turns of 1mm around R6]
100V ceramic or mylar
F1-2 =2A Fuse fast
IC1=STK4036......STK4044

STK40xx power amplifier IC:
STK 4036 > Supply: ±35V - ±53,5V; Power (8R load): 50W
STK 4038 > Supply: ±40V - ±58V; Power (8R load): 60W
STK 4040 > Supply: ±43V - ±63V; Power (8R load): 70W
STK 4042 > Supply: ±46V - ±67V; Power (8R load): 80W
STK 4044 > Supply: ±51V - ±74V ; Power (8R load): 100V

Source: http://skema-elektronik.blogspot.com/2009/06/power-audio-amplifier-based-on-stk400xx.html

Mini Audio Amplifier circuit

2009-10-11T04:09:00.000-07:00

This is very small audio amplifier circuit which can be handled just with 1.5V DC battery. This circuit just need very small power to work.

The maximum output current is I_P=V_P/R_L=62,5mA. If the transistor beta is B=150 then the maximum base current is about 400µA. This is quite much for an amplifier input so a preceding stage is very useful. IC designers normally would even build a 3 or 4 stage amplifier (and e.g. a 20 transistor bias circuit), but our PA should be as simple as possible. For maximum power gain in a direct coupled (best for low component count) amplifier the common emitter configuration is best suited, and a CB or CC stage is much worse. At low voltages a CC also has the disadvantage that the output voltage smaller than the input voltage by V_BE. If you want to drive a CE stage from a CC stage you need an input voltage of 2·V_BE»1,4V, which is nearly impossible form a single cell supply. Two CE stages are much easier to connect, but this makes feedback more difficult because the total amplifier will be noninverting. A solution will be a differential pair which has nearly the same characteristics like a single CE stage but features an inverting and a noninerting input. A further advantage is that the inherent temparature compensation makes the biasing more stable.

more explanation, visit: http://www.weberconnect.de/nfpa2.htm

Digital Volume Control circuit with DS1669

2009-10-05T19:24:00.000-07:00

This is digital volume control circuit which uses DS1669 as the main volume control. This is stereo volume control, you can use stereo push button switch for to control both channel by together.

20W Audio Amplifier circuit with TDA2005

2009-10-03T01:57:00.000-07:00

Here the 20W audio amplifier circuit which use power IC TDA2005 as the main component. The output typical is bridge output. It's mean that the speaker line is not connected tho the grounded line.

Download this file for complete explanation about 20W Audio Amplifier circuit with TDA2005 include the schematic diagram and component list.

7W Audio Amplifier circuit with LM383

2009-09-26T18:28:00.000-07:00

Here the 7 watt audio amplifier circuit that use LM383 as main power IC. The voltage supply for this LM383 should be 5-20 volt DC.

Note:
A 0.2 mF capacitor in series with a 1X resistor should be placed as close as possible to pins 3 and 4 for stability.

7W Amplifier with TDA2003 audio circuit

2009-09-15T19:06:00.000-07:00

Here the schematic diagram of 7W audio amplifier based on IC TDA2003.

Download 7W Amplifier with TDA2003 audio circuit in PDF version HERE

Pre-amp circuit with tone control

2009-08-23T20:16:00.000-07:00

This a 2 in 1 circuit where 2 modules joined in one circuit. With this circuit, you no longer use tone control circuit before your amplifier, but you can add an equalizer between this circuit and your amplifier circuit. In this circuit, P1 is used to control the volume level, P2 to control Bass level and P3 controls Treble level.

This is a mono channel circuit, you need to build another equal circuit to make this circuit has stereo channel.

Part List:


R1__________220K 1/4W Resistor
R2__________100K 1/4W Resistor
R3__________2K7 1/4W Resistor
R4,R5_______8K2 1/4W Resistors
R6__________4K7 1/4W Resistor
R7,R8,R13___2K2 1/4W Resistors
R9__________2M2 1/4W Resistor
R10,R11_____47K 1/4W Resistor
R12_________33K 1/4W Resistor
R14_________470R 1/4W Resistor
R15_________10K 1/4W Resistor
R16_________3K3 1/4W Resistor (See Notes)

C1,C2,C9____470nF 63V Polyester Capacitors
C3,C4_______47nF 63V Polyester Capacitors
C5,C6_______6n8 63V Polyester Capacitors
C7__________10µF 63V Electrolytic Capacitor
C8,C10______22µF 25V Electrolytic Capacitors
C11_________470µF 25V Electrolytic Capacitor

Q1,Q3_______BC550C 45V 100mA Low noise High gain NPN Transistors
Q2__________2N3819 General-purpose N-Channel FET

Amplifier Power Indicator

2009-08-17T19:58:00.000-07:00

This is one of many audio level indicator circuit. The different is that this circuit should be connected tho the output of amplifier while the other indicators connected before amplifier module. This circuit will show the real audio output by LED indicator level.

R1_____________220R  1/2W Resistor
R2,R5,R6,R8____100R  1/4W Resistors
R10,R12,R14____100R  1/4W Resistors
R3_____________220R  1/4W Resistor
R4,R7__________330R  1/2W Resistors
R9_____________560R  1/2W Resistor
R11____________820R  1/2W Resistor
R13______________1K2 1/2W Resistor

D1___________1N4004  400V 1A Diode
D2,D4,D6__BZX79C2V7  2.7V 500mW Zener Diodes
D3,D5,D7,D8,D9,D10   Red LEDs (Any dimension and shape) (See Notes)

Notes:

The output power indicated by each LED must be doubled when 4 Ohms loads are driven.
The circuit can be adapted to suit less powerful amplifiers by reducing the number of LEDs and related voltage dividers.
LEDs of any dimension can be used, but rectangular shaped devices will be more suitable to be compacted in bars or columns.
For a stereo amplifier, two identical circuits are required.

8W Amplifier Based on IC LM383

2009-08-12T03:39:00.000-07:00

This is the 8W audio amplifier with IC LM383 as the main component. Very simple, easy and cheap circuit.

Component part list:

C1 - 10uf Electrolytic Capacitor
C2 - 470uf Electrolytic Capacitor
C3 - 0.1uF Disc Capacitor
C4 - 2000uf Electrolytic Capacitor 2200uF
R1 - 2.2 Ohm Resistance (Anything Within 10% tolerance)
R3 - 220 Ohm Resistance (Anything Within 10% tolerance)
IC1 - LM383 IC

Audio Level Meter with 8 LEDs Indicator

2009-08-05T18:53:00.000-07:00

This audio level meter required 2 pieces of LM324 for each channel. Every single LM324 contain 4 op-amps, then you need 2 pieces of LM324 to cover 8 LEDs. And need 4 piece of LM324 for 16 LEDs (for stereo channel)
Here the schematic:

2W MiniBox Audio Amplifier

2009-07-27T20:57:00.000-07:00

This circuit is simple and cheap, the components also easy to find. This amplifier can be feed by MP3 Player, MP4 Player, Walkman, Mini-Disc, iPod and CD players, computers and similar devices fitted with line or headphone output.

Component parts:

P1_____________10K   Log.Potentiometer

R1,R2__________33K
R3_____________33R
R4_____________15K
R5,R6___________1K
R7____________680R
R8____________120R
R9____________100R   1/2W Trimmer Cermet

C1,C2__________10µF   63V Electrolytic Capacitors
C3____________100µF   25V Electrolytic Capacitor
C4,C7_________470µF   25V Electrolytic Capacitors
C5_____________47pF   63V Ceramic Capacitor
C6____________220nF   63V Polyester Capacitor
C8___________1000µF   25V Electrolytic Capacitor

D1___________1N4148   75V 150mA Diode

Q1____________BC560C  45V 100mA PNP Low noise High gain Transistor
Q2____________BC337   45V 800mA NPN Transistor
Q3____________TIP31A  60V 4A    NPN Transistor
Q4 ___________TIP32A  60V 4A    PNP Transistor

SW1___________SPST switch
SPKR__________3-5 Watt Loudspeaker, 8, 4 or 2 Ohm impedance

Notes:
The amplifier(s) can be conveniently supplied by a 12V wall plug-in adapter.
Closing SW1 a bass-boost is provided but, at the same time, volume control must be increased to compensate for power loss at higher frequencies.
In use, R9 should be carefully adjusted to provide minimal audible signal cross-over distortion consistent with minimal measured quiescent current consumption; a good compromise is to set the quiescent current at about 10-15 mA.
To measure this current, wire a DC current meter temporarily in series with the collector of Q3.

Mini Audio Mixer circuit

2009-07-27T20:32:00.000-07:00

This is simple mini audio mixer. This circuit consume low current due to the simple design. Also featuring three inputs with switchable high/low sensitivity and unusual level-control circuits, providing high overload margins and low-noise figures, proportional to gain-level settings.

Component parts:

P1,P2,P3_________5K  Linear Potentiometers

R1,R11,R15_____180K
R2,R12,R16_______2M2
R3,R13,R17_____750R  (See Notes)
R4,R14,R18_______1K
R5______________15K
R6_____________220R
R7_______________1K5
R8_____________820R
R9_____________150R
R10____________100K

C1,C6,C8_________1µF  63V Polyester or Electrolytic Capacitors
C2,C4,C7,C9____100µF  25V Electrolytic Capacitors
C3,C5__________220µF  25V Electrolytic Capacitors

Q1,Q4,Q5______BC550C  45V 100mA Low noise High gain NPN Transistors
Q2____________BC547   45V 100mA General purpose NPN Transistor
Q3____________BC557   45V 100mA General purpose PNP Transistor

J1,J2,J3________3mm or 6mm Mono Jack sockets
SW1,2,3,4______SPST  Toggle or Slider Switches
B1_______________9V  PP3 Battery
Clip for PP3 Battery

Notes:

When SW1, SW2 or SW3 are open the input sensitivity is suited to high-output devices like CD players, tuners, tape recorders, iPods, miniDisc players, computer audio outputs etc.
When SW1, SW2 or SW3 are closed the input sensitivity is suited to low-output, low-impedance moving coil or electret microphones.
Sometimes, the 750 Ohm value for R3, R13 and R17 resistors could be not easy to find. In this case, two 1K5 resistors wired in parallel can be used to replace each item.
To make a stereo mixer, all the parts must be doubled excepting R6, C3, C5, SW4 and B1.

Universal Pre-Amp circuit

2009-07-20T21:31:00.000-07:00

This is the universal pre amplifier circuit diagram that can be used for common input such us microphone, cd player, tape recorder or other electronic circuit which require pre-amp.

Download the schematic in PDF format

Simple Mixer circuit 3 Input

2009-07-20T20:27:00.000-07:00

This is the very simple 3 input mixer for your audio system. You can add the number of input by adding some components for mixer input (P=10K R=22K). This circuit is only recommend for low and intermediate audio sound system. You need better mixer circuit for your high class audio system.

Here the Schematic diagram:

This is component layout:

And here the PCB layout:

Condenser Mic preamplifier

2009-07-16T16:01:00.000-07:00

This is a very simple preamplifier circuit for condenser microphone. This mic preamplifier also can be used for dynamic microphone.

You can replace the BC549 with BC109C. For better audio result, use ultra low noise transistor BC650C.

14Watt Audio Amplifier + pre-amp and tone control

2009-07-15T04:52:00.000-07:00

This is the schematic diagram of 14 watt power audio amplifier included the pre-amp circuit and tone control circuit. I think this is complete audio system, just need an input and output (speaker)... :)

Use this power supply circuit:

22W Audio Amplifier

2009-07-12T18:11:00.001-07:00

This is simple and cheap 22W audio amplifier circuit for your car audio system or other audio appliances.

20W Audio Power Amplifier with LM1875

2009-07-12T17:41:00.000-07:00

Here the 20W Audio Power Amplifier schematic diagram:

This amplifier use LM1875 which offering very low distortion and high quality performance as the main component.

Feature:
• Up to 30 watts output power
• AVO typically 90 dB
• Low distortion: 0.015%, 1 kHz, 20 W
• Wide power bandwidth: 70 kHz
• Protection for AC and DC short circuits to ground
• Thermal protection with parole circuit
• High current capability: 4A
• Wide supply range 16V-60V
• Internal output protection diodes
• 94 dB ripple rejection
• Plastic power package TO-220

Equalizer 3 band

2009-07-11T17:48:00.000-07:00

This is mono 3 band equalizer circuit. The circuit is simple, cheap and easy to built. You should make two circuits for your stereo audio system.

Supply voltage may be anything from 6 to 30 Volts. Maximum boost 20dB is only realized with maximum supply voltage.

Tone Control circuit

2009-07-11T07:54:00.000-07:00

Here the classic tone control circuit diagram.

This is mono tone control which contain 2 potensiometers to control the level of bass tone and treble tone. You could make the stereo tone control by duplicate this circuit, use stereo potensiometers and add mono potensiometer at input or output for balance adjustment.

8 watt amplifier with TDA2030

2009-07-11T06:23:00.000-07:00

This is cheap and easy audio amplifier circuit diagram.

Actually, the TDA2030 can give you 20watt output, but it was reduced to 8watt for greater output quality...