Help using integrated as power amp

The Rainmakers deserve much better than the 747. There are several options but 1. get a better AV receiver - any of these in the $1500-$2000 range will drive the Rainmakers adequately:

Marantz SR 7005
Yamaha AVENTAGE RX-A2000
NAD T 775
Rotel RX 1550
Denon AVR 4311CI

AV receivers are getting better - more, cleaner power and better isolation of digital parts from analogue parts - not to separates level, but tremendous value because the competition is so fierce (too bad there isn't this same level of focus on 2 channel integrated amps, but that is another story).

This should leave $1k to $500 for 2. a digital set up. Assuming you alredy have a mac mini, you could spend the remainder on a new dac, the new iDAC from Peachtree was well reviewed, and Wavelength and Musical Fidelity have new DACs out as well. The Trusty Cambridge Audio could serve as well.

Another approach is to dump all your investment in a higher end receiver with a quality USB DAC, more power and better preamp section.

I suggest you look at:

Arcam AVR 400
Anthem MRX 700

listen before you buy.

Do you think adding a NAD C275BEE power amp would help the NAD 747 or is it solely the preamp section that you see as the problem. Not sure if it matters but I will almost surely never progress beyond 3.1 - thanks

You could try it, it would definitely control the speakers as long as you are happy with the pre-section in the 747. I am not sure how the C275BEE measures up next to the C272, but I have heard the latter with some decent Triangle and Dynaudio speakers and thought it sounded very good (with NAD C162 pre). The older model amp can be found used for well under five hundred bucks, and the newer one used or refurbished for under $700. The C275BEE should sound at least as good as the C272 and probably better given the upgrade I noticed from the C372 to the C375BEE integrated. If this works for you, you would have extra resources for other gear.

i got at c275bee to drive my Linn keilid speakers and the improvement over bi-amping with the Nad T775 was substantial. Lots more base. You will definatly hear the diff. over a NAD T747.