Bvdiman
C3800 Marantz Pre??
If you mean this, it may have been ok in it's day but to partner it with the stuff we are talking about here and these CLX speakers, it's way out of it's league.
The poor little signal from the source that he has would have to go through a gazillion dirty old contacts switches and sliders, no wonder he may have glare in the upper frequencies, not to mention old caps and out of spec components that would be in this old thing.
If you can read circuit diagrams (linked) just have a look at the crap the cdp signal has to go through before it gets to the output, not on with this hiend gear we are talking about.
This may well be the glare source that the OP is talking about.
To download the file, please go half way down the page.
http://www.eserviceinfo.com/download.php?fileid=48440
Pictures of them here, copy and paste to your address bar
https://www.google.com.au/search?q=marantz+3800+preamp&sa=X&tbm=isch&tbo=u&source=univ&ei=E6auUunJOYfTkwW7tICgBg&ved=0CCsQsAQ&biw=1680&bih=871
Cheers George