Do not buy Singlepower! He ripped me off for $6K on the last amp i got from him. they are also hit & miss on the used market. (mostly miss) The remarks "fraud and crook" are being to nice IMO. Stick with offerings from Headroom or Headamp, or Woo Audio.
Lots of info on www.head-fi.org or www.head-case.org
Lots of info on www.head-fi.org or www.head-case.org