Class B audio amplifier based on TDA1553

Here is the circuit of a Class B audio amplifier based on TDA1553. TDA1553 is a monolithic audio amplifier class B, containing 2 x 22 watt amplifier in bridge configuration load attached. The amplifier operates from 12V DC and develops intentionaly for car audio applications. The IC also has a lot of good features such as short circuit protection, protection of the load dump, reverse polarity protection, speaker protection, etc.

In the circuit, C5 and C4 are decoupling capacitors C3 input, while setting the delay for speaker protection. C1 and C2 are filter capacitors of the offer.

Notes :

• Assemble the circuit on a good quality PCB.
• Use 12V DC for powering the circuit.
• The circuit can deliver 22W per channel into 4 ohm speakers.
• Fit the IC with a proper heat sink.

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1000W ICs audio amplifier with PA03

This is a series of amplifiers are based on the most high-ic power that I have ever known. Because the output is issued up to 1000 watts with the impedance RL 4Ohm. Current supply 120mA, and 30A output current. Minimum input voltage of about 30V and a maximum voltage up to 150V. This is an audio amplifier that I have come across use ICs that maximum voltage up to 150V and output power up to 1000W , the scheme below gan.

Part List

Resistor

R1 = 10K

R2 = 10K

R3 = 220K

R4 = 0.18R 5W

R5 = 2.2R 2W

R6 = 0.18R 5W

Capacitor

C1 = 1uF

C2 = 1000uF

C3 = 68pF

C4 = 1000uF

Inductor

L1 = 4MH

IC

U1 = PA03

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100W Audio Amplifier with TDA7294

TDA7294 is an integrated, monolithic, Class AB audio amplifier designed precisely for Hi-Fi applications. The IC has a DMOS output stage and can deliver 100W RMS into an 8Ohm speaker at +/-38V dual supply.

In the circuit TDA7294 is configured to provide 100W output power into an 8Ohm loudspeaker at +/- 38V supply. C8 is the input coupling capacitor and the input is applied to the non-inverting input (Pin3) of the IC. C3 and C9 are power supply filter capacitors although C10 and C4 are bypass capacitors. C2 is the bootstrap capacitor.

RC network comprising of R1 and C1 improves the high frequency stability of the amplifier and as well prevents oscillations. R2 and C6 sets the mute time constant while R3 and C5 sets the standby time constant. S1 the mute switch and S2 are the standby switch. R5 is the input resistance and the amplifiers input impedance has a direct relationship to its value. R4 and R6 is employed for setting type closed loop gain and With the used value, gain is 30dB. C2 is a DC decoupling.

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150W LM12 based audio amplifier circuit with explanation

LM12 operational amplifier can output currents up to 10A. The LM12 in encapsulated in TO-3 with 4 pins, can support up to 800W and has enough internal protections to prevent slacks from over-currents or over-heating.
You can use LM12CL with 30 V maximum voltage or LM12C with 40V maximum.
The L1 coil has 40 turns 1mm copper, coiled over R4. If you use LM12CL it is recomended to have toroidal transformer 2 x 22V. The output must be between 7 and 12A. Filtering capacitors must have at least 20.000 uF.
LM12 must be mounted with screws on a big heatsink (=<1.5 C/W) and electric isolated form the heatsink

LM12 amplifier circuit diagram

LM12 amplifier PCB layout

More audio amplifier circuits…

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AUDIO FREQUENCY LIGHT MODULATOR ELECTRONIC DIAGRAM

AUDIO FREQUENCY LIGHT MODULATOR ELECTRONIC DIAGRAM

Light has function to replace cable from audio source to speaker. Transformer X2 is utilized to lock the audio signal. VR1 works as the amplitudo modulator from the T1 signal output.

Parts list :

•     Resistor R1:  47k ohm
•     Resistor R2 : 22k ohm
•     Resistor R3 : 220 ohm
•     Diode D1-D7 : 1N4001
•     VR1 : 1k ohm
•     Polar capacitor C1 : 470 uF/25V
•     Polar capacitor C2 : 1 uF
•     Capacitor C3 : 0.1 uF
•     Transistor T1-T2 : BC148
•     Transformer X1 : 220 V AC/0-12V AC
•     X2 : AF output
•     Transistor SCR1-SCR2 : BA654

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100W Hi End Audio Amplifier SymAsym5

Symasym5_3
Symasym5, is a "cute" power amplifier, designed with quality but still low price in mind. This resulted in a ClassAB BJT amplifier, using only TO92 transistors for input and VAS, with a reasonable part count. The topology used is well known and consist of a single diffamp for input, plus a 2nd diffamp with current mirror for VAS. This is followed by normal darlington EF outputstage using modern high beta devices. The circuit uses large amounts of feedback over the whole audioband and an unconventional feedback compensation scheme.
Right now symasym is designed to be driven directly from a CD/DVD-player, simply place a 22k poslog stereo pot between player and symasym. (as voltage divider)

Update

The at least change is to reduce C14 from 22pF to 10pF, but i recommend to follow Pavels advice.

I recommend C14 with 10pF also for MJLs, this increases safety margin.

Do not forget to read Pavels Review! A very promising evaluation of the qualities to be expected from symasym. Thanks Pavel !

Another update are the resistors R31/32 to be increased from 22ohm to 47ohm.

Symasym5_3 is an update of v5.2, with an improved board layout concerning power gnd, resulting in lower thd for high frequencies, giving more clarity in sound. The Page for symasym5_2 still exists.

If the gain is too high because symasym is driven from preamp, R30 can be increased from 499ohms to 1k, but in this case R16/19 (22 or 33 ohms, not on schematic, REs to Q1/2) are required to keep feedback at same level and

Some Specs

• THD: ~0.005% (measured) simd: 0.002%
• Power into 8ohm: 60 watts
• Power into 4ohm: 100 watts
• Gain: 32dB (~1:40)  full output at 0.7v input (0.5v rms)
• Feedback: 57dB
• GainBandWidth: ~400Mhz
• Slewrate: ~20v/us (symetrical)
• Supply voltage: +/- 36v
• Biasing: 55ma, ~12mv across a single 0.22 ohm
• Measurings: RMAA Symasym5  The measuring setup itself is far from perfect, but gives a good idea !
• Frequency response: 3.2hz to 145khz (-1db) using 4.7uf input cap
• Phaseshift at 10khz: <3°
• More will follow !

Schematic

Part List

Transistors:

Device	Qty	Value	Notes
Q1,Q2	2	MPSA18	can be substituted by BC550C (pins reversed !)
Q7,Q8	2	BC546B	or maybe 2n5551 (pins reversed !)
Q3,Q9	2	2N5551	OnSemi/Fairchild/Philips
Q4,Q5,Q12	3	2N5401	OnSemi/Fairchild/Philips
T1	1	BD139	or bd135, bd135-16
U$5	1	MJE15030	OnSemi
U$6	1	MJE15031	OnSemi
U$3	1	MJL3281A	OnSemi
U$4	1	MJL1302A	OnSemi

Capacitors:

Device	Qty	Value	Notes
C14	1	10pF (has been 22pF)	Mica
C2,C7	2	100pF	Mica
C3,C4	2	330pF	Mica
C18	1	47nF	Wima MKS2
C5, C6, C10, C11, C16, C17, C20	7	100nF	Wima MKS2
C1	1	10uF (4.7uF also fits)	Wima MKS2
C8,C9	2	100uF	Electrolytic 63v (at least 40v)
C19	1	470uF	Electrolytic 16v
C12,C13	2	1000uF	Electrolytic 63v (at least 40v)

Resistors:

Device	Qty	Value	Notes
R27,R28	2	0R22	5Watts
R1, R3	2	1R2	2Watts metal film
R4	1	4R7	2Watts metal film
R7	1	10	2Watts metal film
R2	1	10	250mW metal film
R8, R9	2	22	250mW metal film
R31, R32	2	47 (have been 22)	250mW metal film
R26	1	33	250mW metal film
R10	1	68	250mW metal film
R15,R17	2	150	250mW metal film
R11	1	220	250mW metal film
R24,R30	2	499 (or 500)	250mW metal film
R5,R6	2	680	250mW metal film
R13,R23	2	2k	250mW metal film
R12,R14,R29	3	22k	250mW metal film
R18,R20	2	47k	250mW metal film
R22	1	1k pot	Piher, small (470ohm might be better)

Miscellaneous:

Device	Qty	Value	Notes
F1,F2	2	2.5T Fuse	Slow blow
F1,F2	2	---	Fuse holder
L1	1	---	0.6mm isolated (enamelled) copper wire wounded around R7 forming the output coil.

Recomended Part

• All resistors are standard metal film 250mW except: R1/3/4/7, these are 2W metal film, and the 0.22ohm beeing 5W.
  Around R7 is wounded a 0.6mm isolated (enamelled) copper wire forming the output coil. (~12 windings)
  For c19 i used 470uf/16v, all other electrolytics 63v. The 10/100/330pF should be mica-caps.
  The 100nf and 47nf is recommended to be Wima MKS2 (or better), also for C1 i suggest Wima MKS2, 4.7uf is enough.
  For Trimpot i use a Piher. The MPSA18 can be substituted by BC550C, for all other parts i do not recommend changes, especially the feedback network (r29/30) should be kept unchanged, feedback compensation is very delicate for this circuit !
• Be careful when substituting the MPSA18 with BC550C, the pinout is reversed between these 2 transistors !!!
• The bias is adjusted via the trimpot (R22). Recommended bias is 55ma, resulting in 12mv across a single 0.22ohms or 24mv across both 0.22ohms. Connect a DMM to the upper wires of these resistors and adjust trimpot until DMM reads wanted voltage.

Symasym5 biasing: (for debugging)

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Stereo High Power Audio Amplifier

This is a stereo amplifier circuit which has a high output power and excellent sound quality. Amplifier circuit has a very high gain output stage resulting in the deterioration of signal noise distance. This amplifier circuit having an output power of more than 400 Watt x 2 (Stereo) with the speaker impedance 4 Ohm - 8 Ohm. Power supply voltage circuit to supply this high power amplifier with maximum - + 75 Volt DC. Heres the scheme of High Power Amplifier :

High Power Amplifier Circuit Diagram

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HA 13118 bassed 18W audio amplifier circuit and explanation

This audio amplifier circuit diagram is a class AB audio power amplifier based on the Hitachi HA13118 audio integrated circuit . The Hitachi HA13118 audio amplifier circuit provide a high power output from a low voltage supply using the bridge tied load method, and a high gain of 55dB. This audio amplifier is ideal for audio applications where the input signal has a very low level .

The Hitachi HA13118 audio amplifier circuit can provide a maximum 18W power in a 4 ohms load using 18 volts DC power Supply but also can be obtained various output power : > 5W RMS on 8 ohm load using 18V DC supply , > 6W RMS on 4 ohm load using 12V DC supply .

Other specifications for this amplifier are :

S/N ratio : > 70 dB , THD <0.2% @ 1w , freq. response : ~ 30 hz to 30 khz, input level : <25 mv , input impedance ~ 30 k ohm .

For the Hitachi HA13118 audio amplifier circuit you will need a power supply that will provide a DC voltage between 8 and 18Vand at least 1 to 2 Amps.

If you want to obtain the maximum output power you will need a power supply that will provide 18 volts DC at more than 2 A , and if you will use a 4 ohms speaker .

The construction of this power supply is very simple and is require few external components .

Be careful when soldering the IC not to use excessive heat. If it’s possible use some heat sink compound between the heat sink & the IC .

If you need volume control or to attenuate the input signal you can connect a logarithmic potentiometer at the input pin .

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