Bought powerful/expensive Amp+Speakers but plan to use an old preamp , am I crazy?

Honestly, the only way to truly know is to listen side-by-side with another option.

For example, I recently bought a Van Alstine Ultravalve Tube amp for a second tier system (wanted some tube ish) and paired it with a Aragon 24K SP preamp that was modified by Kevin Chambers (power supply and some inernal mods). But I wanted another preamp that could do both XLR and RCA, so I picked up a Schitt Freya+. Also thought the tube preamp with the amp would be one of those "magical" pairings.

First initial listening session? I think I liked what I perceived as better clarity with the Aragon. This is with stock tubes on the Freya+ (I have some NOS Sylvania tubes on the way). Honestly, with all the hype the Freya+ has gotten, I thought it would be the clear winner.

Now, the updated caps are still breaking in on the Aragon and I have no idea how many hours are on the stock Tung Sol 6SN7’s with the Schitt, but this is why you gotta listen to things in your system. BTW, neither preamp sounded bad...it was just a matter of which was doing what better.

(FYI, after Kevin’s mods to the 24K it tested better than the OEM specs of the 28K, which everyone considers the "better" Aragon preamp).

I was in a similar situation: good amp with no volume control, good speakers, but little budget for a preamp. I bought the new Emotiva BasX PT1. The edgy treble was too much for me. I did notice that putting a second preamp, a Xiangsheng 728A, after the Emotiva smoothed things (but preceding the Emotiva it did not). Fortunately, Emotiva honored its no-reason-needed return policy. I stretched my budget to a Van Alstine Transcendence RB 10, which is his budget tube preamp. The setup is marvelous now, detailed without going edgy and musical without going muddy.

There may be synergy between the Paradigms and the electronics. Paradigm is a thoroughly modern speaker with no “musical” coloration. The NAD is a perfectly competent low noise preamp but has no pretense of being High End… no premium parts or heroic power supply. The MA462 gets shat on in these pages, but one thing it isn’t is harsh. That may play well with the new speakers. 

Thank you all for chiming in... It sounds like the consensus is I don't risk damaging anything in the chain using the NAD... but I ought to be saving up for a better/improved pre-amp in the future :)

How would the NAD damage anything?
And who said that?

I specific said “go NAD.”

OMG.  Don't do it.  Your system will blow up and you'll be left with a mess of smoking electronics.  (Seriously, it never costs anything to use what you've already got, especially something you like.)