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about "25w mosfet audio ampfilier"


thanhyuse
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hi thanhyuse,

i don't know how far you are into electronics, but base on your question i could probably presume you are a real beginner. if that is the case my friendly advice is to look for circuits not using mosfets as the output stage and using single rail supply.

but if you insist in building that circuit, pay attention to the following;
R13 & 16 10ohms should be match (same value when tested)
R14 & 15 220ohms should also be match
Q1 & 2 should also be match
you should a single ground point entry
Q6, 7, 8 & 9 should be properly heatsinked

i have build that circuit and it was good, just follow the recommended parts. use high quality electrolytic caps.

hope this would help you :)

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  • 1 month later...

hey, i am having a problem with my power amplifier, it's a 50w PA with audio mixer. I am quite desperate now, i have tried to lessen the humming, indeed it is quite less, but my proff wants no humming at all....what shall i do? please help me out?
thank you very much.

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  • 2 weeks later...

hi!
thank you very much!and you right,i'm a newcomer,so i have many problem,but i will try.
I did this circuit,but not success!something wrong?
when I conect to supply,voltage here drop very fast!!!! :'(
Vbe of Q6<0.6V.
current at Q8,9 very fast.

So again you will help me? thanks all

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hey, i am having a problem with my power amplifier, it's a 50w PA with audio mixer. I am quite desperate now, i have tried to lessen the humming, indeed it is quite less, but my proff wants no humming at all....what shall i do? please help me out?
thank you very much.


Look for any wires that go in to the amplifier. If one shield wire is broken there will be a hum. Also a bad mic will cause a hum. If that does not work then you should look at the capacitors in the power supply section of the amplifier. Also You could spray the controls with some contact cleaner. ( only Use contact cleaner designed for this! If you don't it will ruin the controls for good!)
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