just got a B&K CS-117, lets take a look inside...

[midfi]

plugged in to make sure it worked first, (it does...) it sounds pretty good! but I wanted to open it up to see what I (we) can see and maybe make some small refinements. This is the view of the unit facing you from left to right...







this is facing the rear left to right...





I need a better camera...





I am no electrical/schematic wiz by no ones stretch of the imagination but I'm a good parts swapper :lol:. Will the 4 opamps on this board alter the sound as they do on so many other devices? The opamp in the 1st pic is has M9124 LM 833n, the two in the 2nd pic both have PMI op249 gp T9219 on them and the last one to the far right in the 3rd pic has M9130 LM 833n on it. Any cap or rectifier recommendations? And I noticed the "balance" knob wont turn more than a few degrees clockwise and counterclockwise from center (lots of mechanical resistance), and it has no effect on the balance coming out of the speakers. That looks like a simple pot swap so I ain't really sweating it. I'm not trying to conquer the world, just want to give it a little boost as the bass isn't as defined as my 565gfp (never thought I'd hear myself say that!). What y'all think???

 

[baco99]

resurrecting an old thread.

Do you have a schematic for this preamp? I have one with a new transform and LC7818 IC and it's still not working. Need to dig deeper, but B&K is out of business and they don't have this schematic on the site.