Wiring Schematic Diagram

C1 = 2,2 µF-100 V
C2 = 330 pF-100 V
C3 = 100 nF -100 V
C4 = 100 µF 63 V
C5, C6 = 18 pF
C7 = 100 nF
R1, R3 = 47 K
R2 = 2K2
R4, R5 = 3K9
R6 = 1 K
R7 = 27 K
R8, R9, R11 = 100 ohms
R10 = 10 K
R12, R13 = 470 ohms
R14, R15 = 0.33 ohms 5 watts
R16 = 10 ohms 3 watts
T1, T2 = 2N5401, ZTX558, BC556B
T3, T4 = BF470, MJE350, 2SB649
T5, T6 = BF469, MJE340, 2SD669
T7 = IRF540, IRFP240, 2SK1530, 2SJ162, BUZ900DP, BUZ901DP
T8 = IRF9540, IRFP9240, 2SJ201, 2SK1058, BUZ905DP,
P1 = 2K5 trimmer
F1, F2 = 3 A

power supply
One 2x40 volts 225 VA transformer is exactly what we need for one mono amplifier. For a stereo amplifier, one 2x40 volts 500 VA transformer is required.
Use at least 4x6800 µF 63-80 V reservoir capacitors. The more caps you use, the better the  ripple rejection.
4K7 5W resistors are used to discharge reservoir capacitors once mains is set off.

High Quality, powerful unit: 90W into 4 Ohm load


Circuit diagram:

Parts:
R1______________47K 1/4W Resistor
R2_______________4K7 1/4W Resistor
R3______________22K 1/4W Resistor
R4_______________1K 1/4W Resistor
R5,R12,R13_____330R 1/4W Resistors
R6_______________1K5 1/4W Resistor
R7______________15K 1/4W Resistor
R8______________33K 1/4W Resistor
R9_____________150K 1/4W Resistor
R10____________500R 1/2W Trimmer Cermet
R11_____________39R 1/4W Resistor
R14,R15___________R33 2.5W Resistors
R16_____________10R 2.5W Resistor
R17_______________R22 5W Resistor (wirewound)

C1_____________470nF 63V Polyester Capacitor
C2_____________470pF 63V Polystyrene or ceramic Capacitor
C3______________47µF 63V Electrolytic Capacitor
C4,C8,C9,C11___100nF 63V Polyester Capacitors
C5______________10pF 63V Polystyrene or ceramic Capacitor
C6_______________1µF 63V Polyester Capacitor
C7,C10_________100µF 63V Electrolytic Capacitors

D1___________1N4002 100V 1A Diode
D2_____________5mm. Red LED

Q1,Q2,Q4_____MPSA43 200V 500mA NPN Transistors
Q3,Q5________BC546 65V 100mA NPN Transistors
Q6___________MJE340 200V 500mA NPN Transistor
Q7___________MJE350 200V 500mA PNP Transistor
Q8___________IRFP240 200V 20A N-Channel Hexfet Transistor
Q9___________IRFP9240 200V 12A P-Channel Hexfet Transistor

Power supply circuit diagram:


Parts:
R1_______________3K9 1W Resistor

C1,C2_________4700µF 63V Electrolytic Capacitors (See Notes)
C3,C4__________100nF 63V Polyester Capacitors

D1_____________400V 8A Diode bridge
D2_____________5mm. Red LED

F1,F2__________4A Fuses with sockets

T1_____________230V or 115V Primary, 30+30V Secondary 160VA Mains transformer

PL1____________Male Mains plug

SW1____________SPST Mains switch


To celebrate the hundredth design posted to this website, and to fulfil the requests of many correspondents wanting an amplifier more powerful than the 25W MosFet, a 60 - 90W High Quality power amplifier design is presented here.
Circuit topology is about the same of the above mentioned amplifier, but the extremely rugged IRFP240 and IRFP9240 MosFet devices are used as the output pair, and well renowned high voltage Motorola's transistors are employed in the preceding stages.
The supply rails voltage was kept prudentially at the rather low value of + and - 40V. For those wishing to experiment, the supply rails voltage could be raised to + and - 50V maximum, allowing the amplifier to approach the 100W into 8 Ohm target: enjoy!
A matching, discrete components, Modular Preamplifier design is available here: Modular Audio Preamplifier.
Notes:
• In the original circuit, a three-diode string was wired in series to R10. Two of these diodes are now replaced by a red LED in order to achieve improved quiescent current stability over a larger temperature range. Thanks to David Edwards of LedeAudio for this suggestion.
• A small, U-shaped heatsink must be fitted to Q6 & Q7.
• Q8 & Q9 must be mounted on large heatsinks.
• Quiescent current can be measured by means of an Avo-meter wired in series to the positive supply rail and no input signal.
• Set the Trimmer R10 to its minimum resistance.
• Power-on the amplifier and adjust R10 to read a current drawing of about 120 - 130mA.
• Wait about 15 minutes, watch if the current is varying and readjust if necessary.
• The value suggested for C1 and C2 in the Power Supply Parts List is the minimum required for a mono amplifier. For optimum performance and in stereo configurations, this value should be increased: 10000µF is a good compromise.
• A correct grounding is very important to eliminate hum and ground loops. Connect to the same point the ground sides of R1, R3, C2, C3 and C4 and the ground input wire. Connect R7 and C7 to C11 to output ground. Then connect separately the input and output grounds to the power supply ground.

Technical data:

Output power:
60 Watt RMS @ 8 Ohm (1KHz sinewave) - 90W RMS @ 4 Ohm
Sensitivity:
1V RMS input for 58W output
Frequency response:
30Hz to 20KHz -1dB
Total harmonic distortion @ 1KHz:
1W 0.003% 10W 0.006% 20W 0.01% 40W 0.013% 60W 0.018%
Total harmonic distortion @10KHz:
1W 0.005% 10W 0.02% 20W 0.03% 40W 0.06% 60W 0.09%

A ideal solution for the make a good, low cost power amplifier. It�s a ideal solution for the creation a system of home cinema. 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. …

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



Read More Source:
http://users.otenet.gr/~athsam
Thank you.