Audio Classics has replacements for sale, give Ryan a call. Make sure you check all your crossover components and high frequency drivers. Those super tweeters are fragile. If you see any tanned or brown resistors replace them. All the caps should be replaced if black in color. The yellow ones should be measured. Find your self an owners manual, it will help. This system check out and total rebuild ain't gonna be cheap, but once completed you will have one of the finest sets of book shelf speakers ever designed. You can always contact roger russell over the internet for answers. Audio classics also has upgrades for the tweeter and super tweeter. $$$.