Thank you again for your advice.
I did, however, try the internal EAR transformer with a second MI cartridge. This one is an old Signiture series Grado with a new stylus. In some ways this is a supperior to the Sonata. Warmer, fuller, more extended at the top. Again, there is a gain in performance when the transformer is switched in. With this cartridge, unlike with the Sonata, there is a slight roll-off in the high frequencies. Not with standing the math, I think I may be on to something here. Do you think that a transformer with a 470 Ohm input would reduce this roll-off. Did the other individual with a MM cartrildge you mentioned also find an improvement with the transformer. What inpedance was used there.
Regards, Jim