This 200W MOSFET amplifier circuit designed for single or mono audio channel application. You should build two similar circuits for stereo audio application. Build one first for performance testing to ensure that this circuit really wongking well with great audio performance.

The power supply used for this circuit is a symmetrical / dual polarity type. You need 4 amperes minimum of transformer with +/- 45V output. For stereo application, use about 8 amperes, although the 5A transformer is good enough . You may use the power supply circuit design on this post: 200W Power Amplifier using Transistor

200W MOSFET Amplifier PCB Layout Design

Bottom / Chopper PCB Design

Top PCB Design / Component Placement

Here is the 250W RMS power amplifier circuit called Legend-Stage Master. This is the previous version of Legend-Stage Master MK2. The circuit is based on power MOSFET and give a great output performance for indoor audio sound system.

Over time there is a need for a stronger version of the legend and which serves to lower sound system for gigs and house parties. This gave improvement to this version called Stage Master which is basically not much different from the original. However, the yield and reliability of the power it was necessary to add a degree of excitation, because the output is assigned to two more pairs of MOSFETs, but the total need for excitation and the other parameters increased because of the parallel connection of so many of FET via abilities were VAS the degree of the basic versions.

Specifications:

> Output power : 250W RMS / 8 ohms
> Frequency range : 12Hz-230KHz (-1dB) at 10W RMS
> THD <0.12% (at 1 kHz and 250 W) > THD <0.01% (at 1 kHz and 200W and below this power) > BIAS around 50mA per output pair

250W RMS Power Amplifier PCB Design and Layout

This is the PCB design and component placement for 250 RMS power amplifier, Legend-Stage Master version. In the design, the MOSFETs are both mounted on the PCB and heatsink. If you have difficulty making appropriate heatsink to be mounted on the PCB, you can separate the heatsink from the PCB, mount the MOSFET on the heatsink, then connect the pins of the MOSFET to a PCB using cable.

This circuit designed by Dr Borivoje Jagodic >> original page for the reference.

This is 500W RMS power amplifier circuit design, build based on MOSFET. The circuit is very popular in EE audio hobbyist as “LEGEND stage Master MK2”. It is a very good and powerful amplifier. It uses 12x power MOSFET IRFP240.

To achieve even greater power, and they were often interested young friends, was developed even stronger version is capable of producing a full and true 500W RMS into 8 ohms. With such large forces had to resort to a radically different solution some degree, for even better reliability, or has increased the complexity of the tiles so that for this version is impossible to use the same tile as the previous two lower models (Legend and Legend Stage Master).

Specification:

Output power ——— 500W RMS / 8 ohms
Frequency range 15Hz-130kHz (-1dB) at 30W RMS
THD = <0.18% (at 1 kHz and 500 W)
THD = <0.01% (at 1 kHz and 400W and below this power)
BIAS around 25mA per output pair

500W RMS Power Amplifier PCB Design and Layout

This is the PCB design and component placement, you should mount the MOSFET on the heatsink to prevent overheating and maintain the performance of power amplifier.

This circuit designed by Dr Borivoje Jagodic >> original page for the reference.

Component list:

Use this power supply circuit to handle the 25W HiFi audio amplifier.

Component list:

25W HiFi Audio Amplifier Circuit Notes:

• Can be directly connected to CD players, tuners and tape recorders. Simply add a 10K Log potentiometer (dual gang for stereo) and a switch to cope with the various sources you need.
• Q6 & Q7 must have a small U-shaped heatsink.
• Q8 & Q9 must be mounted on heatsink.
• Adjust R11 to set quiescent current at 100mA (best measured with an Avo-meter in series with Q8 Drain) with no input signal.
• A correct grounding is very important to eliminate hum and ground loops. Connect in the same point the ground sides of R1, R4, R9, C3 to C8. Connect C11 at output ground. Then connect separately the input and output grounds at power supply ground.

Technical data:

• Output power: well in excess of 25Watt RMS @ 8 Ohm (1KHz sinewave)
• Sensitivity: 200mV input for 25W output
• Frequency response: 30Hz to 20KHz -1dB
• Total harmonic distortion @ 1KHz: 0.1W 0.014% 1W 0.006% 10W 0.006% 20W 0.007% 25W 0.01%
• Total harmonic distortion @10KHz: 0.1W 0.024% 1W 0.016% 10W 0.02% 20W 0.045% 25W 0.07%
• Unconditionally stable on capacitive loads