another rookie question - preamp or or power amp

At your budget, I would get these: Kenwood Basic M1 Stereo Power Amplifier and Kenwood Basic C1 Stereo Pre Amp SET | eBay

I owned them when they first came out in the 80’s and doubt that you’ll find a better sounding combination at that price. They were highly revered in the audio community at the time. The variable loudness is a great feature also. The Parasound that you are interested in has a quite high THD (total harmonic distortion). Not in the same league in my humble opinion.  I hope you find what you are looking for.

thanks @ellajeanelle I was hoping to get one component for about $400, to upgrade and then later on upgrade the other component

thanks OP ...

I prefer the look of my other Sansui AU 7700... But i use it no more for now ...

The alpha 607i is a notch over it though in all aspects save flexibility...

It was so amazing that he drives better my headphone K340 than one of the best tube headphone amplifier on the market ...It takes me minute to compare because he beat it on the spot... I never imagined that an headphone out of a 100 watts speakers amplifier will beat a top tube headphone  amplifier with not even a comparison because i lost near 300 bucks in this trial comparison ( save the ratio noise /signals was better on the tube amp because his separate linear power supply was a top notch one). but all others characteristics were better with the Sansui , for example the out of the head impression, the timbre, the deep bass the imaging and soundstage ... The alpha was the top of the Sansui history ... mine is only the first basic model ... Imagine the rare top one existing only in Japan at high price even after 25 years or more ... In my headphone it is evident that the sound is tube like even if it is an S.S. amp... The best realistic timbre i listen too speakers included ...

@mahgister the Sansui looks awesome!

I had always thought that conventional wisdom dictates that "getting it right up front first" yielded the most notable sonic improvements.  And by that logic, the preamp section would be the place to start.

Is there any possibility to try before you buy?  Or to possibly buy from some place like Music Direct and return if things don't work out like you want them to?

grislybutter OP: If looking for an amp only, take a look at a Vintage Denon POA 2200, if you can find one or an Adcom GFA 555.  They are around your price range used and in a different (higher) league than that Parasound. No offense to you or anyone, but Parasound is geared more toward home theater than hi fi.