Nuprime st10 or nuforce sta200, or parasound a23

Hi, in thinking to upgrade my amp  a parasound zamp v3, it's powering a pair of paradigm signature s1v3, looking to improve depth, imaging and mid frequencies .
Despite of price differences, which one would you recommend?
Thanks four your advice
the Nuforce is an awesome deal at it's closeout prices...
Mytek just announced a new 2x300W amp - small and they claim it has Class A triode quality sound.

So I'd want to add that to your listen list.
The st10 is really good and the new Mytek might be good also.
I can't really recommend a parasound,bright and lean in the mids.

Audio Advisor is selling the Nuforce for $499
That's a really good deal,I don't know anything about the sta200 though.

I have one. It's awesome. Based on the Job Goldmund 225. Great review in Absolute Sound. Which also compares it with the Nuprime. A23 was a good value 15 years ago. Not so much now 
Thank all of you for your replies! About the nuforce, does any of you have had a problem connecting spades on the left speaker post? It seems almost impossible because it's positioned  like in a hole.
Also the nuforce review compare very superficially but positively with the nuprime, can somebody confirm this similarities?
my cables have 1/4 inch spades and fit in fine, though I could see how larger spades might be a problem
About the mytek i also checked it, but I will be paying for futures that I will not use, it looks like a nice device though, but thanks for the advice