Help an old man out

Haven’t posted in a while....have been very happy with my system for the last 11 years and didn’t feel the need to really upgrade til recently.  My setup is all my music (and tidal) on my desktop using a Logitech transporter as a DAC through to a Bel Canto pre 3 into a Bel Canto S300 with Gallo 3.1s for speakers.  My S300 is having issues with the left channel (sound level is down to about 50%) so it is accelerating my hunt for something new.  I have really been interested in the NAD M33, as it seems to have everything I need, including a little extra power for the Gallos...they need a kick in the butt to get moving.  Also considering a couple REL subs (probably 512s) to get the low I am not getting right now.  The Gallos are good and tight, but they don’t reach low enough for that nice chest thump.  Anyway, I am reading a lot about poor build quality with NAD and that is making me second guess the direction I am thinking.  Doesn’t seem like there is anything really equivalent at the 5k price point and as nice as some of the 17k and higher Gryphon stuff looks, I have my wife to answer to.  Sorry for the long post, but 5k is a lot of money and I am not a millionaire—just a dude who wants to kick back and listen to tunes at levels I really shouldn’t.  Also, if you feel the itching desire to jump on here and tell everyone how bad class d sucks, just don’t.  We have all heard it before, and we have all seen your amazing graphs of wisdom etc.  thanks for your help!
I had (still have) Rowland 102 - a class D amp based on the same module (200ASC) as your S300.  I liked it a lot, but eventually replaced it with Benchmark AHB2.  It is wonderful, cool running amp, that sounds better than Rowland 102.  Everything is a little bit better - a little cleaner, a little airier, better imaging and a little better bass extension.  The last one surprised me the most.  I use it with Benchmark DAC3 HGC and it is wonderful pair - sonically and visually.  For the cost of NAD M33 you can have both.  DAC3 HGC has analog inputs as well.
I have a nephew, NO ISSUES.. He loves his Nad M33. I can’t remember what he had it was Nad also.. His brother is waiting on his. They are both happy with Nad products.. Understand. one is an electrician..

I’m not so sure a lot of the equipment failures are NOT do to to poor protection. I usually find the two closely related.. I have seen a blown cap or two, on NAD. Been a while though. Sometimes you get a bad batch of parts.. They did AND I’m sure very little protection. Maintaining 120 VAC has only netted me ZERO equipment failure.

I did manage a cable drop that cleared out a few pieces though.. Mercy..

If you bought a pair of Vandersteen 2wq's, you would not only get those bass notes, but your amp would be freed from having to reproduce those power draining low frequencies.
And, they will integrate seamlessly with your speakers. So, for $2K used, including crossovers, you'd be set.
I just googled the Rel subs, I don't see 512, did you mean S/512's?
If so, then you have the budget to buy the new Sub 3's. They have built in equalization.
Another reason to think of Vandy's are the build quality. Many of his 2w subs still work after 20+ years. I know, I sold mine only a couple of years ago.
Very interesting question. The Gallos are known for their good bass response IIRC and a well respected loudspeaker. I don’t think the NAD will take you where you want to go and would be a side step. Class A/B amps are really the kings of good bass control and slam so I would think about a good 200 plus WPC A/B amp. The big power supplies and large capacitors tell you they are designed to store and release power. Also keep you DAC separate, digital designs are still improving so there is no need to tie the two components together. I would just change out your amp and give that a try first. Optimize then think about adding a sub later on.

P.S. Are you using the SA bass amp?
Everything is a little bit better - a little cleaner, a little airier, better imaging and a little better bass extension

exactly what I am looking for...all the reviews say the new Purifi Eigentakt puts class d in new territory, especially for soundstage, which is probably my most important factor when listening. 
just googled the Rel subs, I don't see 512, did you mean S/512's?

yep' those are the ones.  I like their build and their amplification...also the ability to take direct speaker signal rather than line out.  Hadn’t looked at the Vandersteens but will check them out.

Also keep you DAC separate, digital designs are still improving so there is no need to tie the two components together. I would just change out your amp and give that a try first. Optimize then think about adding a sub later on.

I have thought a lot about this as well.  Keeping the components separate means easy change out later on with improvements in technology.  There is just such a plethora of equipment out there and it is difficult to audition anything these days, esp as I am currently stationed in Germany.  Also, I am not using the SA bass amp...I have thought about it in the past, but do not want the fan noise, which is apparently very noticeable.  One of the reasons I want to get the subs is to relax the rest of the sound spectrum so I can listen to more delicate stuff at lower volume but still have weight to the sound...just don’t want a fan interfering with that.

Your speakers are a very low 88dB, which is a shame, your budget could buy you some incredible fine quality if only you had speakers that don't need 500 watts. All the stuff about bass control, forget it, the problem is low sensitivity speakers. Get some Tekton and hear for yourself. 
The Hegel h390 might work, 2x250w and integrated dac. You would need to add a streamer but could start with a Raspberry Pi, the Volumio Primo or Node2i.
"...Also, I am not using the SA bass amp...I have thought about it in the past, but do not want the fan noise..."

The surface noise on a LP record use to hide the fan noise of amps, when I switched to digital I had to get rid of my old amp, the fan was just too noisy. Good call.
Not sure what WAF is, but I don’t see 88dB as very low sensitivity...middle of the pack at best.

@russ69 ,
WAF= Wife approval factor.

And, I don't think 88db is low either, but how hard a speaker is to drive is more dependent upon it's impedance and phase curve.
That's the same BS you hear all the time. It is shocking the number of people unable to figure simple things out and seem to think truth is a democracy.

88 is low, impedance is a crock. Look at all the guys with trouble driving speakers. Why they blame impedance is beyond me. These are the same guys who told me I should get "easy to drive" 8 ohm speakers not 4 ohm, because I have a tube amp. Every single one said 4 ohms will be worse. Everyone except the guy who actually makes the speakers. So I went with his advice. At 4 ohms they are super easy to drive, sound awesome and guess why? 98dB! 

The difference between the 88 you think is "middle of the road" and 98dB is TEN TIMES the power. What I get from my 50 watts you will need 500.

That is reality. 500 vs 50. That is physics. You can make up all the stories in the world, nothing will change the fact that 10dB is ten times the power.

Middle of the road by the way is where you get run down by traffic going both directions. Middle of the road is the last place in the world you want to be. Unless that is you want to be run down no matter which way you turn.
OP — I have a few thoughts to take or leave:

I own an NAD M33.  I think it sounds pretty good.  I’ve been comparing it to my Prima Luna HP Dialogue Premium integrated, using KT150 tubes, in an office sized room.  I’d give the edge to the PL, but that’s my ears, my room, my NOLA Contender 2s, etc etc.  I will say, I continue to dislike the BlueSound environment.  On a less subjective subject, the NAD is not Roon certified, if that matters to you.  Unlike earlier released models that are grandfathered in, if the NAD M33 was sold after Sept 2020, Roon will not recognize it pending certification.  Many online dealers, perhaps in-person dealers, are pitching it as Roon ready.  It’s not.  Lastly, reading between the lines of the reviews and the buzz, the focus with the NAD seems to be its all-in-one feature profile.  Yes, it’s an accomplishment.  I just don’t see a lot of buzz about the sound.  Some.  Not a lot.  

More generally, I think $5k can get you a helluva good amp.  And if you are not philosophically offended by Class D, you might consider some of the amazingly well-priced PS Audio amps.  They’ve been well-received.  I owned the BHKs a few years ago, but I have not heard their Class D stuff.  But, on paper, worth a look.    
Impedance is emphatically not a crock.  Dan D’Agostino would not say that.  Nelson Pass would not say that.  Bascom King would not say that.  Call Nelson and just ask him.  Nominal impedance specs (e.g., "this is a 4 ohm speaker," or "this one’s an 8 ohm speaker") may be unhelpful, or perhaps even "a crock."  Nomical impedance is sorta just average impedance.  But impedance dips are incredibly important, and have little to do with wattage, and little to do with sensitivity.  If a speaker has an impedance dip down to, say, 2.0 or 2.2 ohms at, say, 85 Hz, that speaker is going to be asking for a decent amount of current (not wattage) at 85 Hz.  And a little amp won’t have what the speaker is asking for.  In a way that impacts sound quality, not just volume (which is arguably all that sensitivity numbers tell you; a test tone of 1000 Hz, delivered with one watt, measured from one meter, gives you X volume, in your case 88 dB — although, I suppose if you love listening to 1 kHz tones all day, that could be enormously important).
Turning to the practical: a speaker with sensitivity of 88 dB pretty much never needs 500 watts.  Betcha the NAD, at 200, provides plenty of headroom.  It was plenty of power and current with my Harbeth 30.2s, with their low sensitivity.  And if you don’t feel like really geeking out on impedance dips, etc, I’d vote for you to keep your sights on the 100 wpc and higher amps and chances are you won’t have any power/headroom issues and can instead focus on other priorities (tone, clarity, imaging, dynamics, grip, air, lack of glare).  
My two cents.  Worth about ... two cents.  
i agree with the earlier suggestion of a hegel - h190 or 390 would work well for your power needs

simple elegant styling, excellent sound, plenty of power, very nice remote
JRW,  thanks for the post...agree with you 100%.  The S300 could drive the Gallos okay, but I wanted that headroom and control and the only way to go is up.  
How is soundstage comparatively between your M33 and your Prima Luna?  The reviews I have seen that focus more on the sound of the 33 have said the new Purifis make a huge difference in sound...big improvements over the n-cores etc. when it comes to tighter bass and even lighter highs, which my s300 def lacks.

WAF...that is awesome lol.  Mine is actually very understanding.  She is the one who told me to get the M33, but she is pretty supportive of my hobbies, even when they get expensive.  I showed her the Sonus Faber Serafinos that are on auction right now and she loves them...still waiting for her to tell me to get those!
Headphone dreams/JJS, following your posts I went back and relooked the is definitely a consideration. Looks quality!
+1 jrw1971 re your point about impedance not being a crock.

Aside from his stating the importance of speaker sensitivity Robert Harley states  " Another electrical factor to consider is the loudspeaker's load impedance. ....The lower the loudspeaker's impedance, the more demand is placed on the power amp. If you choose low impedance speakers, be certain the power amp can drive them adequately."

OP -- as between the PL and the M33, my impressions (all the usual caveats):  

M33 has more grip and authority, no question.  More dynamics.  Jump factor.  But sometimes I felt that the bass and lower midrange sounded artificial, as if I had improperly integrated a small, crisp sounding sub.  Or like comparing a drum machine to actual drums.

I've been on a kick recently of hyper-focusing on attack/sustain/decay.  Decay is tricky; too abbreviated sounds nice and crisp and enunciated, but artificially so.  Too much decay eliding into the next note gets sloppy and blurred.  The M33, I think, abbreviates the decay a smidge.  I think the PL gets it right.  But perhaps with some attack edges that are a smidge, well, edgy.  More on this below.

You asked about soundstaging.  To my ears, a clear win for the PL.  More dimensionality.  The way I see it is you have a few scenarios: (i) 2D in a 2D space.  Cardboard cut-out 2D.  Yuck.  (ii) 2D in a 3D space.  Cardboard cut-out players, in a 3D space, giving you some depth and width and layering.  But each player lacks realistic shape; within that 3D space each player is 2D.  That's where I put the M33.  (iii) Then you have 3D in 3D, which is where I put the PL. 

My issue with the PL is glare and bite.  Too much of both, by a smidge.  Countless times over the last 5 years, I will pop it into a system, and think "wow, better than I remember; this thing's fantastic."  After a few weeks, that smidge of glare, edge, maybe a dash of grain, starts to become noticeable.  Countless experiences like this.  

The M33, perhaps mindful of the sins of Class D's past, doesn't do this.  It sounds good.  I like it.  I still use it in my third system.  But it doesn't quite achieve realistic imaging, air, shape, and palpability.  But, to be fair, it now lives in a room, and with stablemates, that don't exactly invite those characteristics.

Last point, I have noticed over several different speakers that the PL can sound a bit boring with particular speakers.  My previous Vandersteen Treo CTs did NOT like it.  NOLA KOs loved it.  Harbeths, somewhere between love and hate.  Wilson Sabrinas sounded awfully good on the PL, even with their not-so-easy impedance dip, but that was a 3-5 day experiment.  Just from a quick google search, I'm getting a hunch that the Gallos want more than the PL will give.

To state the obvious, while a $5k amp gets you sound that's approx 8000 times better than a barebones Sonos system, and forever enjoyable, it will not give you the sound of a $30,000 amp.  Cursed hobby.  In my own case, all I can say is to avoid listening to well set-up, well-matched, uber high end systems.  Hard to recover from those experiences and stay in love with your current gear.  Anyone who says you can get 99.9% of the million dollar sound for under $10k, hasn't heard million dollar sound in a good room.  Long way of saying that I've become a hard grader, and it's something that plagues me with my own gear.  Like you, I don't have unlimited funds, and I also have a wife who knows what "spousal parity" means, because she's smarter than I am.
I completely hear you on the sins of class d past...the brightness, the edge, the almost digital razor on the highs. My S300 was not bad...I say was because I turned it on tonight and the left channel is completely gone now...bummer, no stereo to listen to.
The soundstage was actually very good...very wide. I remember having a friend over to listen once and putting on Space Oddity by Davis Bowie and he asked what speakers were playing...he thought I had my surround sound system turned on. Took him a bit to believe it was just the two Gallos.

the issue I have always had with it was the sibilance in the voices. Amp? I think so...source material is very good, tweeter is very sweet, but always edgy. I have to put that down to older class d.
Like you, I am very analytical, probably overly so. I want to hear everything in its proper space and proper tone. Nothing I hate more than good tone that is stacked up on top of every other instrument, singer etc. some of these producers don’t seem to know how to use a soundboard!

Anyway...sorry for the rant. Not yet sold on the 33...might follow Russ69s advice and keep everything separate and just find some monoblocks I really like or something. Choices choices. Wish COVID-19 wasn’t a thing and I actually had a music shop open anywhere in my vicinity.