lm3886 280watt

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croire

Member
2003-12-19 11:24 am
rouen
i want to build a 280watt with 8 lm3886 ;/channel to make a home cinema

what do you think about this
11.jpg


10.jpg


R7 are 0.22 ohm
+u and -u are +- 40volt
what can i change in the diagram to improve the ampli

cordially
 
from what i understand, parallel amps need to be closely matched as possible. so they are not driving into each others outputs and causing heat and distortion..

each of the 8 amplifiers has 3 capacitors (1 electrolytic even) and 4 resistors affecting the feedback loop.any variation will cause difference in the outputs and distortion.

try and match them as well as you can.

I also wonder what may happen if spike protection was to kick in at different times on the different chips.
 

croire

Member
2003-12-19 11:24 am
rouen
the diagram of the balanced preamp
12.jpg


13.jpg


so i won t use this preamp , i will use the dvr134 or other

in the diagram of the ampli lm3886 i use 1% resistors, silvermica 1% for the10pf=c1, c3=MKP 1%, and C5 C6=1000µf
we can use c1 10pf to 40 pf what is the best for c1

cordially
 
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