a MOSFET amp scheme

[jamesjung21]

Hi.
has anyone ever built this amp before?

http://users.otenet.gr/~athsam/power_amplifier_65w_hexfet_eng.htm

It supplies a PCB pattern as well.
Nice spec.

Please give me a comment on this amp-->

~SPECIFICATIONS~

POWER RATING at 1KHZ with 0.1% THD 63W/ 8ohm, 105W /4ohm
IMD <0.008%
THD at 60W into 8 ohm and 1 KHZ <0.005%
THD at 60W into 8 ohm and 20 HZ....20 KHZ <0.05%
FREQUENCE RESPONSE [at 35W/8ohm, +0...-3dB] 1.5 HZ.....125 KHZ
INPUT SENSITIVITY 1Vrms
ÉÍPUT IMPEDANCE 48K
SLOW RATE with input filter 20V/uS
SIGNAL TO NOISE RATIO [at 1W/8ohm] >99dBA
DAMPING FACTOR at 8ohm [20HZ...20KHZ] >160

 

[djk]

A class B CFP output stage with voltage gain and hexfets, I wonder how it sounds.

I would try it with a NE5532 and just drive the output stage and bias circuit. Drive one end of Q8 and scape everything off to the left of that.

 

[jecanova]

This is the same schematic from Tom Giesbert published in the Elektor magazine. Is a class AB amplifier suited for igbt or mosfet. I´ve build dozens of this and it has a very good sound and low distortion, but the circuit is very treacky. Look for the articles with the modifications needed for the IGBT.
Use small square red leds and match them with the multimeter. Match all paired transistors. Fix the first timpot in the mid point before install in the circuit. The 2nd trimpot must be set to 1 k before initial setings. Do the initial settings with small power voltage (+-20V or less). The Elektor´s pcb has a better design and the courrent transistors are joined to the leds. Remember to match resistors also.
Good look