Power Audio Amplifier based on STK400xx

This is Power Audio Amplifier circuit based on STK400xx series. It's will give you very good quality of sound this circuit is unexpensive too since STK40xx series have low price. It is easy we make a power amplifier using only few external components. The STKxxxx amplifiers, for them we will find in enough eponymous stereo amplifiers , but also in enough activety loudspeakers. They do not need a lot of special knowledge of manufacture, only that attention in pins, in order to they do not break, and one good power supply.

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 Series:

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

High-End Audio Modular Preamplifier

This circuit isn't easy to built but you will get a great audio quality from this circuit. This circuit will give u a high quality preamplifier, capable to drive high quality power amplifiers with good sound.

See the explanation here.

Digital Clock

This is digital clock schematic diagram. This circuit is quite complex and quite difficult for a newbie because this circuit uses IC with some a complicated connections. The voltages that supplied to the circuit are divided in two lines.

Small Surround Sound Decoder

This is surround sound decoder. With this circuit, you can divide the 2 channel (R and L channel) stereo output become 4 channel output that are R channel, L channel, Center out and Rear out. This circuit will enrich your audio sound system.

For full explanation about this circuit, please visit this PAGE

3-3.5 Watt FM transmitter circuit

This is 3-3.5 Watt FM transmitter circuit. With this power, it should be able to reach 3-5 KM distance. The frequency range is about 90-110 MHz.

Component list

Part	Total Qty.	Description
R1,R4,R14,R15	4	10K 1/4W Resistor
R2,R3	2	22K 1/4W Resistor
R5,R13	2	3.9K 1/4W Resistor
R6,R11	2	680 Ohm 1/4W Resistor
R7	1	150 Ohm 1/4W Resistor
R8,R12	2	100 Ohm 1/4W Resistor
R9	1	68 Ohm 1/4W Resistor
R10	1	6.8K 1/4W Resistor
C1	1	4.7pF Ceramic Disc Capacitor
C2,C3,C4,C5,C7,C11,C12	7	100nF Ceramic Disc Capacitor
C6,C9,C10	3	10nF Ceramic Disc Capacitor
C8,C14	2	60pF Trimmer Capacitor
C13	1	82pF Ceramic Disc Capacitor
C15	1	27pF Ceramic Disc Capacitor
C16	1	22pF Ceramic Disc Capacitor
C17	1	10uF 25V Electrolytic Capacitor
C18	1	33pF Ceramic Disc Capacitor
C19	1	18pF Ceramic Disc Capacitor
C20	1	12pF Ceramic Disc Capacitor
C21,C22,C23,C24	4	40pF Trimmer Capacitor
C25	1	5pF Ceramic Disc Capacitor
L1	1	5 WDG, Dia 6 mm, 1 mm CuAg, Space 1 mm
L2,L3,L5,L7,L9	5	6-hole Ferroxcube Wide band HF Choke (5 WDG)
L4,L6,L8	3	1.5 WDG, Dia 6 mm, 1 mm CuAg, Space 1 mm
L10	1	8 WDG, Dia 5 mm, 1 mm CuAg, Space 1 mm
D1	1	BB405, BB102 or equal (most varicaps with C = 2-20 pF [approx.])
Q1	1	2N3866
Q2,Q4	2	2N2219A
Q3	1	BF115
Q5	1	2N3553
U1	1	7810 Regulator
MIC	1	Electret Microphone
MISC	1	PC Board, Wire For Antenna, Heatsinks

Source: electronic-lab.com

Mini FM Transmitter

Here the schematic diagram of mini and simple fm transmitter.

Supply voltage : 1.1 - 3 Volts
Power consumption : 1.8 mA at 1.5 Volts
Range : 30 meters max. at 1.5 Volts

Here the PCB Layout:

Visit this page for complete explanation

3 Line Mixer

Actually, you can modify this circuit become more than 3 lines mixer. Just add and repeat the input parts (P=10K R=22K).

Schematic diagram:

Component placement:

PCB layout:

500 Watt Power Inverter

Here the 500 Watt power inverter schematic diagram.

Designed by: Syed Ashad Mustafa Younus
Revised by: Ronnie B. Tabanao

Click the image to get bigger size of schematic diagram and then save the image... or download the circuit diagram from here