If you have a digital front end with volume control, so can avoid a preamp in your price, consider the Valvet A3.5 solid state Class A monoblocks. They combine the attributes you cite for ASR, with an open, vivid presentation and exceptionally bursty speed. If you need to add an affordable preamp, the Valvet L2 is 6sn7 based and will retain and enhance the same qualities. The fast SET tube amp options that will put it all together will cost more.
Phil
Phil