Is pre-amp getting killed?


Hi,
   I'm in the market for the Pre-amp and DAC. I had the PS audio Stellar Gain Cell DAC/Pre-amp combo and I sold that to go separates. I thought of buying PS audio Direct Stream DAC and Audio Research REF 6 Pre-amp. I started doing research and spoke to few dealers. Below are the recommendations I got,

1. Bel Canto EX DAC
2. Simaudio 390 Network Player/DAC

3 dealers I spoke recommended to go with Pre-AMP/DAC/Network player combo instead of separate Pre-amp and DAC. Is pre-amp's are getting killed by the combo? 

Any thoughts?

karurravi
I really like my Mytek Brooklyn as a pre/DAC. 

Use a home assembled Raspberry Pi for a music server/streamer. $90
I just got the Linear Tube Audio MicroZOTL Preamp and it is a killer unit. I run my DAC to it and it has made my system better.
With a properly designed DAC there is really no need for a pre-amp unlesss you need a phono stage, or have a lot of source devices. My DAC has multiple digital inputs and a single analog input. The output of the DAC is touted directly to the amplifier. It works for me. 
Even if you have only digital a preamp is still useful; one way is if you want to run your interconnect cables a long way to the amplifiers (which might be sitting by the speakers with short speaker cables). Many digital products have poor volume controls, so that is another way preamps are still quite useful to obtain better sound!
@erik_squires - What OS are you running on your Raspberry Pi? I have 2 RP3's running an older version of Moode. Doesn't really meet my expectations as a user friendly music server/streamer. A newer version might be better, but a different OS might be an even better answer.