Hello all, I have SR-507/SRM-310 combination and I wonder what Stax amp I should look after if I upgrade this combo? I love how SR-507 sounds with this amp but you know, we all want to upgrade our units somehow. The only Stax combo I have auditoned to date beside mine was SR-009/SRM-006ts. That was really unmusical, very thin sound unexpectedly. Since I still feel that 507/310 has harmonious sounding combo, 507/006ts may suit better. I'm satisfied with SR-507, I'd like to upgrade the amp only. You tell me the most suitable amp with it maybe. Thanks.