Switch to silver for a treble boost?

If you really want to change the stereo's sound then change the Stereo. The whole kit and kiboodle.
Use an old all tube pre with out of controll gain like my ARC (idle for now) Then employ a class D switching amp like the 500 wpc Spectron III its got digitistis in a minor key only. Then Spend a few bucks on using Silver lace cables from Home Grown audio. They are not really in the same league as Signal and I own both.
Finally make the funeral arrangements for the Maggies get a spine and just let it go. Then buy some enormous German horns that sound like a razor. No blankets just nice clean Avant Garde Trios the German horns. Hide the Maggies elswhere for a year or two or else you go back to Momma.

I didn't read all the posts so I don't know if this was mentioned already. If the 602's have dual binding posts, try getting rid of the brass jumpers. Make your own with a couple of short copper pieces. Second, run your cables into the tweeter binding posts and let the jumpers take the signal to the bass. At the most these will only help a little but it's FREE and every little bit helps. Good luck.

Onemug,

Agree.

Knownothing,

Ahhhhhhhhh, Great minds! ;-)

I found that the inclusion of excellent power cables really opened up my system