Who needs a Preamp??

For sure an active preamp is better then 
a passive gain stage on a dac or Cd player with a volume control.andanother point the oppo has a few hundred dollars in parts speaking of the 205 .you get what you pay for.a active preamp has much bigger power supplies and much better 
dynamics,also much more $$. I have owned all types and owned a Audio store for years ,any good active  preamp will give you a bigger more stable performance.
vacuum tube preamps enhance the performance further still.

I have always said and experienced that there is nothing like a good preamp in a system. YMMV but my systems have always sounded best with an active preamp.

I will remind folks that The Truth preamp is a wonderful option with an input impedance of 6 trillion ohms and and output impedance of 3 ohms.  If your source puts out 1.5v or more of output, then you are good to go.  They all do today. No impedance issues to deal with.  In terms of the amp you pair with it, ideally it should be relatively sensitive with full volume attained with under 2 or so volts.  

You can use 30 foot long ICs with no issue.  Worth looking into for $1000. 

A "Good" Quality Active Pre-Amp brings the "Life, Soul, Emotion" to the Music.

Technically, seldom needed, but a lot of music played through my Modwright 36.5 in the chain produces an emotional response in me that is kinda like the first bite of a hot fudge sunday...an "ahhh."  The 36.5 replaced the output attenuuator in a high-end DAC.