Impressions on the NAD M51

[Hdale85]

Lol, no worries I'll check them out another time.

[JonMarsh]

Well if I was going with NAD, I'd probably go with 2 Master Series Direct Digital Amplifiers if I was going to pick a NAD Amp.

I've heard the XPA-2 and it was not my thing... I thought it was a little too bright, so if that's the case then it could be that I wouldn't like NAD's amp.

But probably for the price of NAD's amp... I'd probably just use my hookup for Classe CA-M600... since I can't really find anything anyone has bad to say about the amp...just more if someone likes more of a warmer McIntosh type sound, or Brighter Krell like sound.

But whatever I do... might not be this year at all... so I'll happily stay with my RB-1090 especially now with it's upgrades I've done to it... much better amp than it once was.

The direct digital amps are using the same Zetex controller chip set that the M51 does- actually, it was used first in the amplifiers, as the Zetex chip converts everything to a PWM output at a high carrier frequency (850 kHz in the case of the M51).

[PewterTA]

Hmmm... in that case I might like the sound of them then!!!

I just found out my Rotel & Classe dealer in Cleveland had to break ties with B&W Group so I'm thinking I won't be able to get my very nice discount on the CA-M600 anymore.... So that might be the end of me thinking of going that way. Reason is they merged with another Audio store and must've been conflicts...

On the upper note, they now sell NAD! ha ha

[spaceteddy]

I have read the tread, seems like no one has experienced this: I recently "upgraded" my setup. I replaced my NAD M5 cd player, with NAD M50, M51 and M52. I have retained my NAD M3 and B&W 804D. I use XLR between DAC M51 and M3, just as I used between M5/M3. Problem: I can't belive how much the bass has disappeared. I's like almost half the amount of bass left. It sounds like it's actually something wrong? It's also very crispy (that is actually a good crispy, the problem is the bass. When I connect my old M5 directly to the M3 with RCA, the good natural sound with nice deep bass and whole soundspectre is back. It's the same crispy basslacking sound regardless if I am listen to CD through the M50, music from the M52 music voult, bluray or other sourches that goes through the DAC. Everything is correct connected ( as far as I concern ) I just can not live with this downgraded sound. Hope someone has the answer! Thanks Bjorn

[JonMarsh]

I'd suggest taking your components back to your dealer and auditioning them there, and seeing if what you hear is the same. Also, double check your cable polarity, for the speakers, and make sure you don't have things out of phase. I use an M50 and M52 with a TotalDAC-D2 and there's plenty of bass, and the M51 works fine in a different system. Sounds like a setup issue, or a defective component.

[spaceteddy]

Also, double check your cable polarity, for the speakers, and make sure you don't have things out of phase.

Thanks for reply.
Checked the speakercables, it's good, and since the sound is perfect with M5 to M3 I suspect it is something wrong. I think people without knowledge would say the sound is good, but I know how much the bass has dissapeared. I will contact my dealer and have it checked. TS says:

Now that I've had the NAD M51 in my system for the last week listening to it. I have to say my thoughts on the NAD have changed some. First bass... whatever happened to the M51... something "broken in" or "finally got to optimal performance" About, I would say, the 20 - 30 hour mark, all the sudden the bass just EXPLODED from the unit. The level of bass depth, power, speed, accuracy, and tactility is well... pretty darn impressive. I'm noticing much deeper sound with a lot more power. It's almost like adding a subwoofer to the system....or well... turning the volume up on it at least.

How was it really before it broke in? Is it that BIG difference? Anyone who have changed from the same setup and could share their thoughts

[JonMarsh]

Not to dis Pewter, but having one of these a long time, and having benched mine out of the box, I wonder if he just was playing some different albums or material, or just turned it up a bit? (loudness effect/compensation with the human ear?)

Take both your units in to your dealer, and have him check them side by side. Most likely to get accurate results. BTW, the M50+M52 is a VERY nice sounding combination, very well reviewed in comparison to more expensive music servers of it's type. I do use mine only with the AES-EBU connection. Which digital interconnect are you using with your setup?

[spaceteddy]

Yes. Using the AES-EBU. Dealer next...

[mthucs]

Gungnir vs M51

Hi Guys,

Did you ever get a chance to do a side-by-side comparison between the NAD M51 and the Schiit Gungnir?

I'm about to purchase one or the other for similar prices (NAD being 300 dollars more expensive).

Any thoughts would be appreciated.

Min

So what you're saying Bill is you didn't like the NAD...... I mean that's what I'm hearing... and that I need to get rid of it and that you'll help take it off my hands.......


*Yawn - shakes head* What was I saying again....

The real test I think will be when we have the Audiophile get together meeting and can place the NAD and Schiit Gungnir side by side and switch between the two.

I'm glad you liked it Bill... I think his greatest compliment came in the form where we were talking about my Media PC that I've finished up (Windows 2012 r2 Server with Paul Pang's USB 3 Card and Audiophile Optimizer utility), so the music was low enough that we could talk at normal volumes and Bill just stopped mid sentence and said he couldn't believe how amazing the bass sounded at such a low level, then he listened more and said the entire spectrum is represented so perfectly that it's just sort of amazing that it can play that low and that well.

Anyone that wants to come over and hear it, the door is open and Beer is in the fridge.

[PewterTA]

Yes we did do the comparison. I think the M51 was slightly better. The big difference was in the soundstage, it was open and wide, where the Gungnir is slightly more closed and smaller of a sounds stage.

The highs, lows and in betweens are very very similar. Maybe the slightest hand goes to the M51. The instruments might have a little more air around them. But honestly it's pretty much splitting hairs.

Now I will say the biggest help (to both DACs) is the addition of transformer isolation. This has made a noticeable improvement in both the Gungnir and the M51. Enough that you can take the shielding off and notice a difference over when it's on.

[wkhanna]

As Dan said, we auditioned Dan's stock NAD 51 & my stock Gungnir in my system.
The NAD won out handily, but the differences are subtle.

[jim1961]

Is the new C510 everything the M51 was? If so, at $1300, sounds like a bargain.

[JonMarsh]

In many quarters the thought is that the C510 is basically an M51 with less expensive front panel metalwork and a manual volume control added.

I haven't heard one or seen, but should this be the case, the value proposition is pretty clear... :W

[jim1961]

In many quarters the thought is that the C510 is basically an M51 with less expensive front panel metalwork and a manual volume control added.

I haven't heard one or seen, but should this be the case, the value proposition is pretty clear... :W

I dont know the credibility of the sources, but looking into blogs where folks listened to both, several, not all, felt the C510 was inferior. At only 60% the price of the M51, it would make sense that the C510 gave up something.

Believe it or not, I still havent heard my brothers M51. But that is supposed to happen in the next month or so. I intend to compare it critically to my Rega DAC. If its close, ill keep what I have. If the M51 blows me away, I have a choice to make. A M51 or C510. And in such a case, I really need to find out if the C510 is indeed inferior.

[benthe8track]

I dont know the credibility of the sources, but looking into blogs where folks listened to both, several, not all, felt the C510 was inferior. At only 60% the price of the M51, it would make sense that the C510 gave up something.

Believe it or not, I still havent heard my brothers M51. But that is supposed to happen in the next month or so. I intend to compare it critically to my Rega DAC. If its close, ill keep what I have. If the M51 blows me away, I have a choice to make. A M51 or C510. And in such a case, I really need to find out if the C510 is indeed inferior.

I got my M51 used (2 years old) for 900. It's a good value if you can find a similar deal.

[jim1961]

I got my M51 used (2 years old) for 900. It's a good value if you can find a similar deal.

The advent of the C510 should be driving down the price for used M51's, especially if the perception is that they are equal.

$900 is an excellent price. The best ive found lately is $1200 - $1400. Not moving on it till I hear it though.

[JonMarsh]

An advisory for you- though the built in digital volume control is as good as any on the market, unless you have a low sensitivity system and are running the volume control turned way up, you should use these with an external preamp. This is the case whether we're talking M51, Beerkeley Alpha DAC, AURALiC Vega, or TotalDAC-D1 Dual. The only DAC I have for which that is not the case is the Metric LIO-8, which actually uses a separate low noise analog stage for the output volume control.

[benthe8track]

An advisory for you- though the built in digital volume control is as good as any on the market, unless you have a low sensitivity system and are running the volume control turned way up, you should use these with an external preamp. This is the case whether we're talking M51, Beerkeley Alpha DAC, AURALiC Vega, or TotalDAC-D1 Dual. The only DAC I have for which that is not the case is the Metric LIO-8, which actually uses a separate low noise analog stage for the output volume control.

I agree, I used the m51 as a preamp for a few months until I bought my BP26. There was a noticable improvement when I added the preamp.

[wkhanna]

Timing is everything......

I was just over at Dan's last night listening to his system that now runs his Nad M51 through a Classe CP-800 pre.

As good as the M51 is, it is better (to my ears) with the CP-800 between it & the power amps.
Subtle, but more musical. A softening that accentuates the realism of the instruments.

JMHO YMMV

[jim1961]

An advisory for you- though the built in digital volume control is as good as any on the market, unless you have a low sensitivity system and are running the volume control turned way up, you should use these with an external preamp. This is the case whether we're talking M51, Beerkeley Alpha DAC, AURALiC Vega, or TotalDAC-D1 Dual. The only DAC I have for which that is not the case is the Metric LIO-8, which actually uses a separate low noise analog stage for the output volume control.

Instead of an external pre-amp, wouldn't a stepped attenuator preserve the analog signal path better?

[wkhanna]

IIRC, Jon uses these LINK

[jim1961]

IIRC, Jon uses these LINK

I do too. The 25K version

[JonMarsh]

I have a passive preamp using Shallco switch based attenuators, but I only use it these days sometimes for speaker testing.

the problem for me is necessary cable lengths and format- I pretty much only use balanced interconnections (remember, the TotalDAC-D1 dual is a fully balanced DAC, i.e., the two signal polarities are generated by separate discrete converters (R2R ladder DACs) and with other DACs like the M51 and the Vega, I use the balanced outputs, too. With the physical setup I have, I need to run 3-4 meter interconnects to the power amps, and that doesn't work well in a passive attenuator system.

I do have an Ayre K5 preamp, but it is a bit soft in both the bottom and top and, and not the last word in transparency in the midrange, though for it's time it was and is quite "musical". I'd describe it's sins as mild ones of omission, and quite mild at that.

OTOH, I found the Cambridge 840e preamp to have the extension and transparency I was looking for at a reasonable price, and balanced outputs and a couple of balanced inputs. the relay ladder volume control was one of it's features and bugs, having very well controlled attenuation tracking but not being as reliable as needed.

That led me to investigate the Cambridge Audio 851e, which has a total of three pairs of balanced inputs, has lowered THD+N by an order of magnitude (I suspect they're using a particular series of TI op amps that I'm using in the front end of my "revived" Class D design, and they have a "solid state volume control", which is not one of the chips used in AVR's, but from bits I've pulled up in various sources appears to be some type of multiplying DAC chip; that it, it's an R2R ladder which is used as a resistive attenuator. I played around with that in the 90's, but just didn't have time to build any hardware (young daughter).

The build quality and materials are quite a bit improved on the 851e, so anyone considering an active preamp really ought to take a look at it, especially considering the very reasonable price. Now, if you want something similar in audio quality, and are willing to give up two balanced inputs and the 12V control interfaces, the defeatable tone controls, and input labelling and a control display, but gain something a bit more stylish and compact, and paying a few hundred MORE, then the AURALiC Taurus Pre is worth a close look, and might be your cup of tea. I'm getting one for the "mobile" sound system for demoing and testing the Class D hardware in development (new Class D oriented SMPS for my day job, new modules as a skunkworks project, though rest assured I have both nCore and top of the line UcD modules for comparison already).

For now, the 851e is in the reference system with the TotalDAC-D1 and Brainstorm DCD-8 with a 10MHz rubidium oscillator. I have a second oscillator and a Mutec MC3+ which will be used with the AURALiC Vega. yes, I have gone little bonkers buying this extra gear, but the size and weight are quite a bit reduced, and I didn't want to be taking the big pieces in to work or down to El Segundo or to CES or APEC conference.

YMMV, etc, I'm just relaying what I've found to work for me in my circumstances and needs and expectations. I will say it is not easy to find a really good $2K preamp, though one would think it shouldn't be THAT hard these days. But the small boutique companies don't offer the functionality and value proposition I need at this point- $2K is my threshold of pain, I guess, and you rarely get balanced inputs and outputs galore at that price point, with everything else top flight in the signal path. (The 851e at 0.00045% THD? Try matching that- it means both the distortion AND noise have be very, very low.

How to do that? take a look at the TI LME49720, LME49860, or even the "low buck" version in this series, the LM4562.)

Everyone likes to talk a good talk about designing their own low noise, ultra low distortion line stage, and I was doing that back the 70's and 80's, with very good results considering the state of technology those days. Matching these TI parts, with their very low noise figure, very low THD, very high PSRR, etc, would be very tough and expensive. Analog IC processing has learned a lot in the intervening 30 years...

If I was ever to do an active crossover, it would likely not be a DSP design (with how many channels of DAC converters for the output?) but an ASP such as Linkwitz did for the Orions or the custom crossover I built for ThomasW's living room system (IB sub, Acoustat 1+1 mid bass/low midrange, RD72 upper midrange, and Panasonic leaf ribbon tweeters. OTOH, I do have a dipole system on hold in development which will be digital...

but hey, I'm old school, and I know it. The baseline setup I would consider for a digital multi-channel crossover is my Metric Halo LIO-8/ULN-8 (I bought a LIO-8, but have done the upgrades necessary that it is now a ULN-8). 8 Channels of A/D and D/A, with quality comparable to the Berkeley Alpha, but at a much lower price per channel! They list for about $4500, but when they run promotions, you can get them cheaper; I see B&H Photo offering them for about $3500 right now. But to program and set one up, you need to have a Mac with a Firewire connection (not included in the newer ones, but easily added with a Thunderbolt to Firewir converter.)

[wkhanna]

Fascinating stuff, Jon!

[JonMarsh]

Reading that this morning, I realize I did ramble on a bit too long... my apologies... no one to "share" with locally!

But my comments stand... just one person's view- certainly interested in hearing about results from others!

[jim1961]

Reading that this morning, I realize I did ramble on a bit too long... my apologies... no one to "share" with locally!

But my comments stand... just one person's view- certainly interested in hearing about results from others!

Your rambles are more informative than many other peoples self viewed facts :T

[JonMarsh]

One more hint to drop into the grab bag- Hypex sells interconnects optimized for high RFI environments (class D amplifiers, anyone?) and I've recently gotten a 3 meter set of XLR balanced to try out, and I'd say so far they rank high on the value proposition scale- very non-micro phonic easy to handle, and no complaints about the sound. Note, this is the more expensive HG version, not the ST version.

More feedback as I get more experience with them.

[Chris D]

Exactly, Jon. If you can't vent and ramble on here, there's on point trying anywhere else!

[JonMarsh]

Exactly, Jon. If you can't vent and ramble on here, there's on point trying anywhere else!

Ain't that the truth... most moderators would kick me off for wandering off topic! Or steering right to the very edge of it!

[jim1961]

Finally did the DAC shootout between the M51 and my Rega DAC.

I thought the M51 was a bit more musical. Smoother in the upper mids, where lesser DAC's and CD players seems to falter the most. The two DAC's were much closer than I would have guessed. Overall, the M51 won. But only by a bit.

[wkhanna]

my experiance based on actual listening has revealed that once you get into the over $1k DACs' differences become subtle. And personal tastes in how one 'wants' their music to sound become more influential in one's judgement of performance.

natural qualities from vocal & un-amplified acoustic instruments are what i focus on.
also, it takes time listening to to equipment to garner the true characteristics of a piece of equipment.
first impressions can often be be misleading simply cuz our brains are used to what they are used to.

when i put the NAD against my modified Gungnir, the NAD won easily.
but it was subtle.
nuance of things like piano sustain, string timbre and smooth, natural sibilance of vocals were evident.

I hate to resurrect platitudes, but when we get to the level of the NAD, the rule of diminishing returns rears its head.

I like the NAD a lot cuz it hits all the buttons I crave based on my personal preferences.
and even more so does the Bricasti M1, but that thing is 4x the entry fee for not whole a lot more performance. And at this level, you will need some fairly high-dollar speakers & electronics to discern the true capabilities.

just some humble thoughts thrown out in a fury of not enough time to explain in more detail.

please forgive if i sound crude.
not intended.

[jim1961]

Not crude at all. Good points, all.

Its true I had only a few hours with the unit. While I played some familiar material, not all of it was. There is no doubt diminishing returns comes into the equation.

Comparing a $200 all-in-one Cd player to a 1K transport + 1K DAC is one thing. Comparing a 1K transport + 1K DAC to the same transport and a 2K DAC is another. I was hoping to find a weak link. Secretly, I was hoping the NAD blew away my Rega. Used NAD's can probably be had for around $1000, and I could sell the Rega for $400 on Audiogon. So I was prepared to spend $600. But the Rega DAC did pretty well against the twice as expensive NAD.

It may be in the years to come that the performance offered by the M51 can be realized by $500 DAC's. The performance per dollar keeps improving.

[wkhanna]

......... But the Rega DAC did pretty well against the twice as expensive NAD.

It may be in the years to come that the performance offered by the M51 can be realized by $500 DAC's. The performance per dollar keeps improving.

Agreed!
And that is a V good thing for all of us, imho.


Totally OT, but I thought you might appreciate this.
Started playing with REW...

Here is shot of my room we took a few weeks ago.
Still learning how to use the display options.......ops:

[wkhanna]

here is another of the same sweep:

edit, I am using a version of Jon's 65 liter bottom ported Natalie Portman's with two subs next to each speaker running from desecrate L/R inputs crossed at ~ 90 dB.

[jim1961]

15db hotter in the treble/upper mid region vs the bass. Is that by design?

Might help to add some smoothing, maybe 1/24th (lack of smoothing probably making the high end look hotter than it actually is).

[wkhanna]

[wkhanna]

a new thread has been started so as not to clutter this one regarding my learning of REW software here:

LINK