Should I add a Preamp to my system

I would certainly look at the Herron audio vtph-2a phono pre, which can be the cornerstone of any analog front-end. It’s remarkable. I heard the Brooklyn at RMAF - not a good medium. I had a well regarded ss pre but prefer tubes. my inbound is a tube dac 😊 Cheers

Schiit, man. The Freya +. 

I had similar dillema to Yours. I have Berkeley Alpha DAC with digital volume control to my active Backes&Muller speakers and think dont need a preamp. In the manual of Berkeley they said: If You dont want loss fidelity dont use a pre.
I tried some budget pre and overall sound was worst. 
Next I tried better preamps of my friends in my system ( Mark Levinson no26, Sonic Frontiers SFL-2) and I like it more.
Finally I bought tube Joule Electra LA-150mkII and couldnt be happier, now sound is more palpable, rich and colorfull with ubeliveble weight.
So summary, If You want preamp it must be really the good one

Jolida Foz SS-X Sound Stage Expander.

Knock your socks off.

You are always better off with an analog volume control. You should always try to run your digital sections full tilt for maximum definition. Digital volume controls lose definition as you drop volume. Analog controls do not. I am not sure what the Mytec is doing. But if it is using an analog volume control another preamp would be a waste of money. Save it for a better amp, speakers, music or flowers for the wife.