Mark, this is one piece of audio equipment that is relatively safe to buy used. You have a tube preamp which will give you that tube sound regardless of the amp you use. In your case you want a SS amp with as much power as you can get like a newer Parasound unit or Bryston. An AB amp with a high damping factor and direct coupled. Class A amps are a little more dangerous to buy used because of the heat. Just like a light bulb if you turn them on and off enough they eventually blow their output section. I had a Krell KMA 100 do that to me after 20 years of service and a Pass amp do it to a friend.