In this setup I made the copy of an original Philips wOOx sw 988 home theater subwoofer. Te story behind of it is simple.
My parents got one at home, a bit more than twenty years or so. It haven't got any hearable disorder around 19 years of working.
Some months before we've been watched a moovie, and the sub just stayed so silent all the time. Like the master gain only adjustable between 0 - 10%. I decided to take it apart, and measuring all the components to see, what went wrong.
Then It turned out a capacitor dried out over the years in the differential amplifier sector.
A 35V 47µF one.
I replaced it, now works as new!
