For great control and full range depth, to stay in your price range, I have to recommend the Pass Labs X250. I had tried many amps, tube and solid state, and the Pass gear fit the bill the best for me. The most pleasing tube amps I had heard with my SC-5s were the Audio Research amps. Enough so that I bought the ARC, and them traded it in to buy the Pass instead. I have no regrets of having the Pass gear, even now (especially now) when I hear other amps. Best Regards.