I think you should live with yr amp as is for a while, then try out biamping using a cheap SS on the woofers. There's a Quad selling here for $600 for example.
Your amp is a good performer for its price and "upgrading" it to better drive those speakers will cost a lot of money: a big Krell for example, or a big Symphonic Line or Mac or a Mark Lev...
Your amp is a good performer for its price and "upgrading" it to better drive those speakers will cost a lot of money: a big Krell for example, or a big Symphonic Line or Mac or a Mark Lev...