The size of the power amp you need has to do with the efficiency of your loudspeakers, how large the room is, how loudly you want to play your music, and how much power your loudspeakers can safely take.
If you can use your existing integrated amp as a preamp, then get a power amp first. The amp you quote, the Parasound 2125 power amp, is NOT available at $400, so why even talk about it? There are a number of good value amps at $400 or less on US Audiomart. Why not go there to look for one?
another rookie question - preamp or or power amp
I have a decent integrated amp ("decent" - to my ears). SS, 50Watts to 8 Ohms. It has a preamp output.
I have been looking at used power amps and preamps in the 2-400 dollar range.
For example: the Parasound 2125 power amp, the Parasound P3
This is an OR question. Which choice will yield a better improvement,
1) if I put a preamp before my integrated so the integrated acts as the power amp
or 2) if I use my integrated as a preamp to a power amp?
It's also a choice to sell my integrated and save up until I can buy both a power amp and a preamp, but obviously I am itching to try one of the above options.
My room is 15x13 so I am not sure I need a big power amp (big: 100Watts?)