Pre amp Vs CD/DVD player with output control

I think you can do it much better than anyone who will suggest in this post.
From the tech stand point, your amps can be driven with no preamp.
BTW how's LS16? doesn't it have too much gain what 'time' of volume control do you normally listen?

Look into the new Burson Audio HA-160D. It is a high quality DAC with USB inputs for computer or digital coax for use with a simple transport. It also has a great sounding 24-step ANALOG attenuator AND 3 switchable sets of RCA inputs. Another added bonus is it can be used as a fantastic sounding headphone amp for either it's DAC or pre-amp analog inputs. For around $1000 new, its very versatile.

Digital volume controls do not lose resolution if properly implemented. If your D/A is processing data at 24 or 32bit resolution, then you will not lose resolution at any reasonable volume setting. Wadia products are designed to work perfectly well without preamps. On the other hand, some people just like how a dedicated preamp sounds in their systems regardless of colorations introduced.