DAC as pre amp

Why would you need a second input ?

if using the dac , -preamp just go straight out to the amp , you should check out 

on back .

I resisted buying a preamp for a long time. 

Me too. My Matrix Element X provides pretty good source-switching and volume control (as well as a very good DAC). However, it does not supply the same signal boost (4.5 vrms, XLR out) as my Benchmark LA4 preamp.  The Element X does have a 10 dB output boost, and my Benchmarlk AHB2 power amp has an input sensitivity switch. Together, these 2 controls help with gain-matching.  For low level listening, here may be a subtle SQ improvement from inserting the LA4 between the DAC and power amp. In my system, for my ears, this alone would not be enough to easily justify the added expense and clutter. But you do get other benefits from it (including an extra set of analog inputs, 2-way 12v trigger, and balance adjustment).

@knotscott  I am far from alone in this stance and indeed I wasn't even the first to post it  (in other threads).  Frankly, I don't come up with many of my own ideas (like Xerox, I get) but am good a building on the wisdom of others.

To me, it seems a poor design of an amp to not support various levels of input and indeed I have never had a amp that required more output than my DAC could provide.  That said, I haven't tried a lot of DACs.  I have a Chord DAVE and LOWERING the output voltage of the DAC is a recommended way to combat harshness in your system if you have that problem.  The Chord Qutest actually has switchable output voltage and I have used it on the lowest setting with no problem.

The one group who is consisitenly fully supportive of the preamp, and often emotional about it, as you appear to be, is the group of people who have invested a large sum in a preamp.

I'll close by saying that we are saying the same thing, you just want to dress it up by saying the coloration is "improved performance".  Ok.  That's your definition.  But any preamp, except possibly a passive preamp, especially a transformer based passive preamp, is going to add it's own color to the signal.  It processes it just like an amp.  Every amp sounds different, every preamp sounds different.  

I'm glad you like your preamp.  I prefer my sound as naked as possible, as close to what was recorded on the original tapes as possilbe.

Jerry

Theoretically, every component in a system causes coloration. I suppose we all have a preference about how we'd like it to sound.

There are always good and poor examples of every design approach, so exceptions occur.  What I'm saying is that it seems that more preamps currently do a satisfactory job of overcoming whatever obstacles are posed by the signal and the amplifier load than DACs at this point in time.   That could certainly change in the future.

I have had the same experience as the OP. In my case I have a somewhat vintage (late 90's) Krell KRC-2 pre. My theory is that the volume control quality likely has something to do with the superior sound in a pre. We do most of our listening at lower volumes where the line level signal is severely attenuated. A good pre and its volume control are optimized to insure that there is no deterioration in the sound at lower levels. A DAC is really a line level component and the volume control is not critical to its function. In fact, many DACs have digital volume controls that reduce the resolution as the volume is lowered.