Value of a preamp?

+1 @soix  and @jl35 

Fair number of preamp lauding threads on here. A few more people praising their dacs volume control sans external pre. "Richness" was the term used that I thought described it best, in my system anyway.

The one value that rarely gets mentioned is the ability to control the interconnect such that it eliminates any artifacts. However, this will only happen with a pre-amp that supports the balanced line standard (AES-48) and connected to an amplifier that supports the standard as well. It's how I do it in my system.

Vintage Preamps are loaded with Features that Integrated Amps typically omit:

Balance; Two MM Phono Inputs; Tape Loop; Mode Switch; Filters including Fletcher Munson 'Loudness' for Low Volume Listening; Match Gain for 3 inputs (volume stays the same as you change Inputs)

more info here

A good tubed preamp will greatly enhance your sound period.