there was a huge change from the DA-1 to the DA-1.1. The drivers, wiring posts, and crossovers are all different as well as internal mid compartment and bracing. So there is no way to upgrade a DA-1 to the current DA-1.1, the best I can do is to upgrade the wiring and some of the internal tweeks for $1,000 for the pair. I tried to make this change ok for my customers by giving them a substantial discount if they wanted to buy the new model or the Ulysses, this seemed to work well and a lot of people got great deals on used DA-1's!
thanks,
Lou