Thoughts on recapping my B&K Ref 50

I seem to have a fair amount of hiss from my tweeters and a very faint buzz in the mids when this is turned on and it’s only when this pre amp is connected to my amp... other pre amps are quiet but considering its age I’m thinking about going in and changing out some capacitors.

Has anyone done this to this particular pre amp, I don’t have the series 2, so I’m not sure what the differences are.

I surely would not wanna go backwards in sound quality with this so I am not sure where to start in terms of bringing it back to life.

I’ve considered the new outlaw 976 with its straight through analog section, but I’ve never had a chance to listen to it yet.

All input and criticism is well appreciated.