Receivers kind of limit your options.
If your receiver offers pre outs, you can add a power amp but the degree of improvement depends on how good (or bad) the receivers power amp was to begin with and how much "better" the standalone power amp is.
As far as adding a preamp to a receiver, it ain't that easy. To avail yourself of whatever advantage said preamp might offer, you would need to connect it's outputs to the receiver's power amp inputs, which many receivers lack.
Receivers don't generally accept preamps "in line" with their other processing.
Ok, let us go to a specific case....
Having an integrated amplifier (Nad C-340) running Paradigm Studio 100. The Nad integrated has pre-out to add a power amplifier if you want.It is only 40 watts by channel. The Studio 100 recomended is 50 watts minimum, I believe. If you add a decent power amplifier using the Nad C-340 as a preamp in direct source mode Can it improve the system?
Thanks,
Jorge
Depends on the power amp.
If it has significantly more power and is of at least the same quality, then yes.
Remember, a barely audiable increase of 3db headroom takes twice the power.
It does sound like you're pushing that lil amp, though. Shoot for at LEAST 100 clean watts. More if you ca nswing it. Even then, it will be barely audiable but you should have a little more headroom for those power hogs.
Yes, last weekend I was at my dealer but...
I didn't take my credit card with me and I could't bring to home a Musical Fidelity A 3.2 which they has as a room demo. It was an opcion. Another is an Acurus A-200 which is 200 watts by channel. I want to know what will happen after adding a better power amplifier. I have given a vote to the Nad preamp section but I don't know what will be the result. I am going to let you know.
Thanks,
Jorge