Would This Amp Be Worth The Cost?

I love the preamp.  That is very much the digital module within the M33 and is an awesome value.  There is a surprising bias against Classic series stuff from NAD.  That is a great unit.  

I would partially agree with the sales rep.  It is not the fact that your amp is a Class D, it is that particular Classe amp is a bit older and not quite as refined as some of the more recent class D units that have been produced.  The NAD C298 would have passed it by in terms of tech and sound quality.

It isn't inherently bad, there are just amps that can give you more and if you bought it recently, you probably paid less than $1500 for it and that is an awesome amp for that price.  I sold one not that long.

That MF amp is great.  Tons of current and will have control over the drivers, just as he pointed out.  There are other options, but that amps is a strong value and is well thought in terms of pairing with your speakers.  

It will sound more natural than your Classe.  It is a great product.  

Ozzy - well, that’s odd, because folks keep posting that the changes they hear when swapping cables, adding a Schumann resonator, placing a crystal on top, auditioning at their local store, etc, all reveals almost instant results!

Don’t worry about me!  I love my source material, my speakers, and my rooms. I worked with audio designers who helped me get the ideal speaker and room set up for me (and my son), and I followed their advice. As it happens I had an amp built for my son’s studio too!  All are fit for purpose.  The sound is fantastic.  The investment was where it mattered. On the designers’ express advice, nothing was wasted where it doesn’t matter. That custom amp?  Kettle chord is what the designer recommended. Standard fuse too - any way around I wanted. 
I just worry about folks getting ripped off for $1000s by merchants whose claims, under any kind of scrutiny, just don’t stand up. You see them here all the time - cries for help : “I need a cable that will give me more bass”... and there is no shortage of people saying “get these, they sound great, and only $2000 per meter!”   It’s plain wrong.  

Hi Greywolf.  At least check out the Starke A4-320 amp. Priced right, a USA company, sounds as good as the Purifi modules in the NAD M33 and the LKV power amp. Super value! 4 (bridgeable) channels for the price of 2. Linear power supply, no switching noise radiating into your other equipment. I have three of them powering 11 channels in a 5.0 system using Linkwitz LX521-4 speakers as the stereo pair (each side a 4 way with one amp per speaker - 8 channels for the stereo pair - electronic crossovers.). Excellent results powering Magnepans, too. Keep Smiling! It's music we want to hear, yes? Why spend money on cosmetics? Save your money for music and concert tickets. Enjoy!

I would expect you to see a decent improvement with the MF amp. improved dynamics makes music much more enjoyable and your speakers deserve a better amp. 

you should also look at a power conditioner called PSM156 by puritan audio. check out the comments on Audiogon.

You will hear big improvements with clarity, separation and timbre. You will hear what your current amp is really capable of and it will improve the pre amp too. 

@bluemoodriver, the DBT you posted is hysterical. Between the "high-end system" and 5 dudes in the sweet spot, you're really making quite the case. I can't believe they weren't able to tell the difference! LOL