The specifications of the Sumiko Blackbird (cartridge weight 9.6g, compliance 12 microns/mN) suggest that it should pair well with the SME IV tonearm for a combined resonance frequency of about 10Hz. As long as the output of the cartridge (2.5 mV) is compatible with the gain in your Rotel phono stage, you should be in good shape. If your Rotel phono stage is a standard 47k Ohm moving magnet phono stage, you should be in business.
To be safe, however, it would be good to hear from someone who has experience in mounting the Sumiko Blackbird on the SME IV or V series arms - just to be sure there are no physical compatibility problems between the cartridge and the tonearm.
To be safe, however, it would be good to hear from someone who has experience in mounting the Sumiko Blackbird on the SME IV or V series arms - just to be sure there are no physical compatibility problems between the cartridge and the tonearm.