Hi, I have a faulty Beolab 8000 speaker. The Fuse F1 (4a 250v slow blow) on the transformer board is blown. However, it is a type I haven't come across before - circular (shaped like old style metal cased transistor) with two legs that just plug into the fuse socket. Can anyone advise me where i can get such a fuse. Part number is 6600068. Regards