So would you try for the 7500A if you are looking for one? My old 7500 lost one of the rear chan many years ago and I just got in a service manual for it and I might be able to fix it and maybe not? But I was happy with it. I am the one also that has the problem with the 8001 that you replyed too and I am going to open it back up and see what I can find. Thank goodness it opens up better than the 7500 ones, the 8001 is easy to get to the top side anyway.