I was hoping this would be cooler… but in the end it wasn’t.
I had these speakers trailing me from office to office for the past 10 or so years. I picked them up when I was working at Cardinal Commerce up in Mentor back around 1999 or 2000 or so.
They worked just fine until late this spring around the time I broke my leg. Even then they worked, but they had this odd buzzing sound that started up one day after I got back from lunch. Odd buzzing sounds at around 60Hz from something plugged into the wall concern me.
I unplugged it and it sat waiting to be torn down for quite a while.
Until today when I finally took it apart.
Cavalierly I ignored the “Caution: no user serviceable parts inside.” As it turns out there is something that could be serviced — though it wasn’t the problem.
After removing a slew of screws, including two under the the rubber feet and one under the sticker the guts were out in the open.
Holy sea of capacitors, Batman!
Just from looking at it there’s a full-wave bridge, a voltage regulator and a mess of capacitors to smooth out the voltage.
Speaking of user-serviceable — there’s a perfectly serviceable fuse there complete with directions on replacing it!
Surprisingly, the back of the borad was populated with a few SMDs.
The brains, no doubt, are the pair of power amps connected to the massive heat sink:
First, the bigger one — the TA8229K low frequency power amplifier:
And the smaller one, a BA5417 power amp for the smaller satellite speakers:
I would have torn things down further but I didn’t want to take out a saw. The rest of the enclosure is held together with copious amounts of glue…
In the end I think I might have figured out the buzz… though it’s not worth putting things back together. My guess is that the rubber bumper on the top of the heat sink was starting to bang against the side of the slot it lived in:
Of course I made that realization after a butchered the side. :-/
That being said, I’ve long since replaced this with a better one that sounds cleaner and has some more features as well.
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