I just ran across something really wild. This applies to Beta Lead and Beta Bass. If your serial number is less than A-31084 there is a Service Bulletin (#38) that applies. The Level pots R200 and R180 are changed from 25K (23-1111) to 100K (23-1110). There are a couple of other component changes but the above will give you enough info to check your amp if the serial number is below A-31084. Some amps may have been updated in the field as a result of this Service Bulletin. Installing this mod gives you 12dB more gain between the CMOS and the poweramp. I'll be able to post more info next week when I get a scanner.
