امپلی فایر قدرتمند 20 الی 80 وات - نسخه قابل چاپ +- Parsi Coders (http://parsicoders.com) +-- انجمن: Electronics and Robotics (http://parsicoders.com/forumdisplay.php?fid=149) +--- انجمن: Electronics (http://parsicoders.com/forumdisplay.php?fid=150) +--- موضوع: امپلی فایر قدرتمند 20 الی 80 وات (/showthread.php?tid=3648)

امپلی فایر قدرتمند 20 الی 80 وات - a.mehran - 09-05-2014 Some comments: - The first thing that you must do, is to measure the end transistors (T3 and T4) amplifying coefficient, the hfe or β. If their disagreement is bigger than 30 %, the amplifier would not give a clear sound. I used MJ3001 and MJ2501 transistors, and this disagreement was around 5%. - Before the first “turning on” you must short circuit the inputs of the amp, and put a mA-meter on the output, than turn the amplifier on, and tune the R13 pot, to decrease the DC current on the output, to some uA-s, or in a lucky situation to zero. I was able to decrease it to 10 uA .