MosFET Power Amp Module. 100 watts output at US $ 100. American
IC driver merged with Japanese power MosFET plus JFET input stage.

　　　　　　　　　　 MosFET Power Amp module 　

Specifications :　

Rated output 90 watt class AB with 8 ohm load at +/- 55 DC supply volt.
Max. output 100 watt class AB with 4 ohm load.
Freq. response 5Hz to 1 MHz at -1dB to -3dB.
Total harm. dist. 0.01% at 1 kHz 8 ohm load.
Input sensitivity 500 mv at 100 watt output power.
Gain 30 times (29 dB)
Slew rate 45 volt per uS.
Input impedance 10 kilo ohm / 100 PF.
Damping factor 250 under class operation.
Buffer isolation 120 dB between pre-amp and power amp
Output offset Output offest voltage less then 1 mV.
Board size 100 mm x 170 mm.
Features Maiko's bench mark, wide bandwidth and high slew rate amp

Maiko MosFET power amp.

The output character of the power MosFET is a combination of bi-polar transistor and vaccum tube that produce a unique sound effect more adopted to human listening. By making use of the American IC driver to generate a high signal voltage swing, forcing the Japanese Power MosFET to work at its best linear region with fast switching mode. Such approach created the near one MHz bandwidth amplifier with a very high slew rate of 45 v/us. The advantages of MosFET is fully exploited here.

The JFET input stage formed a buffer between the pre-amp (another board) and the IC driver, such that both stages will work independently at its optimum performace. Nulling the buffer offset pot will adjust the power output offset voltage to zero.

The stand alone +/- voltage regulators are purposely assigned for the IC driver, ensuring the IC operated as its specification stated. All by-pass capacitors are well lay out to prevent oscillation caused by the high input impedance of the FETs.

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To DIYer, We suggest :

The sensitivity of the mosFET power amp is 250 mv, the CD drive output is 2 volt, thus using 2 mosFET module and 1 HV power supply, a 2x100 watts stereo amplifier with a bandwidth of near a MHz and a slew rate of 45 V/uS is built as picture shown.