Anthem STR preamp vs Integrated amp preamp section


Hi all, I'm having trouble really finding good info about this.

I currently have the Anthem STR Integrated Preamp.  But wondering if I should sell it and just get the STR preamp and use my PS Audio m700 amps.

My main question is, what are the main differences in the preamp sections?  Different dac?  Different processing?

I'm not totally comfortable understanding everything on their spec sheets.

Thanks
dtximages
@dtximages
I understand it has a USB input but does it accept a direct digital feed as a music source from an iPod/iPhone/iPad that bypasses the i device DAC and uses the STR DAC? Not all do but some that don't support the direct connection will work with the Apple CCK Lightning to USB Camera Adapter. 

I'm not concerned with streaming airplay.

Thanks
@george_r  Gotcha, I'm not sure.  I don't see why it wouldn't but there are many more knowledgeable than I.  I do know that if you connect via USB then you're using the Anthem's DAC so there's no need for an "i device" dac.
I agree, it should, I hope it does, but I can't be the first person to want to connect an iPhone/iPod/iPad. Odd getting a clear answer has been a challenge. I guess I'll know when I get my STR preamp in a week or so.

I just don't want to have multiple DA/AD/DA conversions.

Thanks.
I think the consensus would be that streaming anything straight from your iphone would be considered an inferior source in the first place.  If you can afford an Anthem STR product, why wouldn't you get a dedicated streamer like the Bluesound Node 2i or something?  
@dtximages, I have no interest in streaming?  I want a direct digital connection  via lightning to USB to the STR DAC.

Regards