I'm guessing the Accuphase is a solid state amp, and if that's the case, a modern solid state amp will offer sonic advantages over what you have. A relatively inexpensive amp that I can recommend is the W4S ST500 with WBT outputs. They also make an integrated STI 500. If you are ennamored with Accuphase, check out some of their new models.
If it is a tube unit, you may not find a significant improvement.
If it is a tube unit, you may not find a significant improvement.