ProJect Pre BOX S2 as preamp

I have read the reviews of this unit, however have not read much discussion on it's use as a preamp. I would appreciate hearing from those having experience using it as such. Will use it in a second system with different amplifier/speaker combinations of ~$2500 retail price. Thanks in advance for any input.
It’s most likely it will not work. Most phono preamps do not have enough voltage to drive a power amp. You will need to know the output voltage of the Project. I doubt that it is more than 1 volt!
It’s not a phono preamp.  
You can easily use it as a pre-amp. It uses an ESS DAC, so it uses its its own internal 32Bit datapath to do volume control, so no issues.
Yes, it is a headphone amp, preamp, and DAC, hence my interest. Likely use it with a Dynaco St-70 having 1.34V input sensitivity and a NewForce STA200 having 0.45 input sensitivity. 

ProJect does make a Phono Box which provides maybe 40dB gain such that with many MM cartridges would not reach 1V output.
looks like a lot of gear for $399--haven't heard, but previously used a project head box and was impressed with the build and sonics, esp. at the price--very uncolored and clean-sounding