I had a 2000 model 55430 with 5v preouts and I moved up to a 2000 55040 which is right below their flagship model. The 040 has 8v preouts and I did notice a difference once I got everything tuned. They're a great deck! I can't remember the model #'s for the new ones, but the top-o-the-line one looks like one awsome deck. With the copper plated chassis and 8 volt outs you 'll have crystal clear sound!