Spend more money on the amp or the pre-amp?

Hi thehorn,

yes, exactly - this was meant to be a more theoretical/academic than applied question. Your insight is interesting and seems to make sense. It is interesting to hear that many folks find an integrated amp to be the best value at those price points. Because I’ve heard elsewhere that "separates are always better".

Concerning my system(s) specifically, I listen to CDs and google play streaming Via airport express airplay.

system 1:
KEF Q Compact speakers
NAD 304 integrated (just got the audioquest interconnects)
Rega Planet CD player

system 2
Wharfdale Diamond 10.7 speakers
Marantz PM6005 integrated
Marantz CD5004

I was thinking about purchasing an amp to pair with the NAD, but I’m not sure I love the NAD - it sounds pretty muddy/bass heavy with the KEFs. Would a higher powered amp clean up this sound?

Thank you for your thoughts thehorn!  Much appreciated. 

Though I cannot afford the jump from the NAD ($120, Craigslist) to a $1000 integrated tube amp. Though I will certainly keep those options in mind. :)

I'm more interested in the best possible "mid-fi" I suppose. 

I love the KEFs and they seem to be suited to my room (10'x15'). But I have the bass turned halfway down on the NAD and they still sound a little muddy sometimes. 

Another thought I had was to use the NAD as the amp and get the best sounding $200 preamp I could find. 

Update for anyone interested:

Got a Rega Brio-R off Ebay ($430) for the KEFs.  Sounds fantastic.

Got a NAD 7175PE off Audiomart ($170) for the Wharfdales - sounds really great.

Thanks everyone for all the thoughts and ideas - really helped me to sort through things.