Hello! I have two Beta 58's that I had never examined until yesterday and I discovered that they don't look the same. Here's a comparative picture: I think the one on the left is the oldest one but I'm not at all certain. I tried gently to see if the plastic cover on the right one, which I guess is a popkiller of some sort, was removable but I didn't dare to try harder risking to damage the membrane. Is there a way to determine which one is oldest? I can't really hear any difference between them but I figure older = always better. And another quick question, I use these to record vocals (it is an amazing microphone for my voice) and I've always used a regular mounted popkiller and I wonder if I can/should record with the microphone cover/lid screwed off like in the picture? It struck me that it seems a bit unnecessary to have double the popkilling? Actually this is what led me to start this thread as I discovered the difference between the mics when I tried recording without the cover.