I have now successfully replaced the three bar tweeters on my A3s with drivers built up from Celestion 3s. I have put on extra ring magnets to act as Faraday rings, and they sound better than the originals! Power handling is amazing. The Celestion 3s 5s and 7s all use tweeters that have the same titanium dome/diaphragm as the A series, but a different magnet assembly and front. You can pick up a pair for next to nothing, and then take the tweeters to bits and reassemble using parts from the blown A series tweets. If you are careful, the resulrts are fantastic.