Did you build this amp?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hello,im new on this forum and i want to build an audio amplifier with irfp 240/9240 and i found this very simple schematic,i want to put 2 pairs of final stage,and remove all diodes includin the zener diodes,and betwin the colectors of 2sb716 /2sd756 put a superdiode stage,what do you think,it will work?regard,Adrian!
 
Sorry,my mistake,here is the original schematic
 

Attachments

  • 100 watt mosfet power amplifier.gif
    100 watt mosfet power amplifier.gif
    12.6 KB · Views: 173
Member
Joined 2010
Paid Member
When you see the zeners added as an afterthought, you can be be fairly sure that it is not a well planned design. The parts shown and rail voltages have all been changed at some time. Are these your amendments? According to the gate resistors and the balanced VAS design, it probably started as Hitachi's Lateral Mosfet application note design.

I think it will "work" but not with those bias arrangements or 60V rail voltages. How long do you think the input pair will survive? How many output pairs are needed with 60V rails and real 4R loads?

Simple designs can be good but they take a lot of careful planning to ensure that they work reliably when there are no safety circuits to prevent disaster. I'm afraid this is just too basic and not thought through as a complete power amplifier. There are many other simple, proven designs here on the Forum that will be much better for the small extra cost and assembly time.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.