I am a new member and found this forum while looking for info on JBL L200 Studio Monitors. I purchased mine new about 47 years ago. They have been stored safely in our basement for quite some time. I just had them brought up and placed in my living room. They have a great history but have been silent for about 25 years. I read some members mention L200A and L200B. How do I know which ones I own?