60W MosFet Audio Amplifier

High Quality, powerful unit: 90W into 4 Ohm load Also suited as guitar or bass amplifier

60W MosFet Audio Amplifier

60W MosFet Audio Amplifier Description

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.

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

240W MOSFET Power Audio Amplifier

240W MOSFET Power Audio Amplifier

A high power audio amplifier circuit which can output up to 240W on a 4Ω speaker.
This mosfet amplifier is built with BUZ23 and uses a 40V symmetrical power supply. Connect the NTC close to the heatsinker.

MosFet 240W power amplifier schematic

240W MOSFET Power Audio Amplifier

400 Watt MOSFET Operational Amplifier

Features:

• HIGH INTERNAL DISSIPATION — 200 WATTS
• HIGH VOLTAGE, HIGH CURRENT — 200V, 20A
• HIGH SLEW RATE — 50V/µS
• 4 WIRE CURRENT LIMIT SENSING
• LOW DISTORTION
• EXTERNAL SLEEP MODE CONTROL
• OPTIONAL BOOST VOLTAGE INPU

APPLICATIONS:

• SONAR TRANSDUCER DRIVER
• LINEAR AND ROTARY MOTOR DRIVES
• YOKE/MAGNETIC FIELD EXCITATION
• PROGRAMMABLE POWER SUPPLIES TO ±95V
• AUDIO UP TO 400W

Circuit Diagram:

Equivalent circuit 400 Watt MOSFET Operational Amplifier

Pin connection for 400 Watt MOSFET Operational Amplifier

500W MOSFET POWER OPERATIONAL AMPLIFIERS PA05A

Features

• high internal dissipation - 250 watts
• high voltage. high curent - 100V, 30 A
• high slew rate - 100V/uS
• 4 wire curent limit sensig
• low distorsion
• external shutdown control

Description:

The PA05 is a high voltage MOSFET power operational amplifier that extends the performance limits of power amplifier  in slew rate and power bandwidth, while maintaining high current and power dissipation ratings. The PA05 is a highly flexible amplifier. The shutdown control feature allows the output stage to be turned off for standby operation or load protection during fault conditions. Boost voltage inputs allow the small signal portion of the amplifier to

operate at a higher voltage than the high current output stage. The amplifier is then biased to achieve close linear swings to the supply rails at high currents for extra efficient operation. 

EQUIVALENT SCHEMATIC:

Circuit diagram for 500W MOSFET POWER OPERATIONAL AMPLIFIERS PA05A

External Connection

4 x 50W quad power amplifier TDA7564B

Features:

■ Multipower BCD technology

■ MOSFET output power stage

■ DMOS power output

■ New high efficiency (class SB)

■ High output power capability 4x28 W/4  @ 

14.4 V, 1 kHz, 10 % THD, 4x50 W max, power 

■ Max. output power 4x72 W/2 

■ Full I2C bus driving:

– Standby

– Independent front/rear soft play/mute

– Selectable gain (for low noise line output 

function)

– High efficiency enable/disable

– I2C bus digital diagnostics (including AC 

and DC load detection)

■ Full fault protection

■ DC offset detection

■ Four independent short circuit protection

■ Clipping detector (2 %/10 %)

■ Linear thermal shutdown with multiple thermal 

warning

■ ESD protection

Description:

The TDA7564B is a new BCD technology quad bridge type of car radio amplifier in Flexiwatt25 / PowerSO36 package specially intended for car radio applications. Thanks to the DMOS output stage the TDA7564B has a very low distortion allowing a clear powerful sound. Among the features, its superior efficiency performance coming from the internal exclusive structure, makes it the most suitable device to simplify the thermal management in high power sets. The dissipated output power under average listening condition is in fact reduced up to 50% when compared to the level provided by conventional class AB solutions. This device is equipped with a full diagnostics array that communicates the status of each speaker through the I2C bus.

Circuit Diagram:

4 x 50W quad power amplifier TDA7564B