Should I add a stereo preamp?

I have Paradigm S4 v1 speakers driven by Emotiva UPA-1 amps. I am currently using a Pioneer Elite VSX23. Would something like a Parasound 2100 improve 2 channel performance compared to the receiver? I am using a sub and everything is connected to the receiver digitally to avoid adc to dac for using the crossover.
Hi Danny:

What is the source that you are using and what specifically are you attempting to improve on? A few weeks back, there was a thread by a poster who had invested about $7k in amps & speakers, but was driving the whole rig with an inexpensive blu-ray player.

generally speaking a good standalone preamp will sound better than using your mainstream avr as a preamp. similarly (and perhaps to expand on rar1's point), you'll likely get better sound with good standalone dac than using the digital ins on your avr. if you'd post your whole setup, your budget and your objectives, you'd likely get some good advise as to where to go from here.
I had a similar experience, was driving my fronts with a Denon AVR, also used a sub. 2 channel was barely as good as my 15 year old Yamaha receiver, and the Denon is a $900 AVR, discounted. My first head unit was a 10 year old Yamaha CD changer, then upgraded to a Denon DCM 270, which was an improvement, but still the mids were thin. I added a Rotel 2-channel amp and things got better, but I finally bought the Parasound Halo pre and it was a big improvement. My head unit now is a laptop pushing lossless rips into a V-link, then to the PS Audio DLIII. I built a dedicated 2-channel rig tho, I don't run 2.1...another good pre amp with bass management is the Anthem TLP-1, that's what I was looking at.
I use to run some paradigms. I was using their statement amp with a 3k denon receiver as a preamp . Switched to a paradigm avm30 and heard a huge difference . I think a different controller or a dedicated preamp would make a big improvement for you as well .
For music sources at the moment I am using a PC playing flac files on foobar2000 though the coax out of a nuforce udac2. (The analog outs go to a headphone amp). I also use a Macbook playing ALAC connected to the receiver via toslink. For analog, I have a Audio Technica Atlp120 tt with Shure m97xe. As far as my goals, I would like analog bass management so that I can use my sub with a better outboard usb dac. I also want a decent phono pre as I am currently using the one built in to the turntable. And lastly,although I'm not sure if a preamp would help, I want a bit more preaence of the midrange. Basically I want to know what I can do to get to most out of my speakers. Sorry if what I'm saying doesn't make sense. This is my first real system.
Oh yeah, forgot to mention ht bypass is a must as this is also my 5 channel movie system. Thanks.