Mytek slams Hypex in Stereophile Amp Review


Mytek's chief designer, Michal Jurewicz, told me. "Hypex [class-D modules] cannot drive it, the amps collapse, but this Brooklyn Amp does it with ease."

https://www.stereophile.com/content/mytek-brooklyn-amp-power-amplifier

Which is pretty interesting, because the closest I could find to their specs is from ICEpower modules. :) 

I've not been able to do comparisons with Hypex vs. ICEpower amps, so I have no idea what this is about. I use both but certainly not with difficult speakers. 
erik_squires
If your going to copy and paste something from an article, you shouldn’t do just part of it.

” "Duntechs, with their multiple drivers and complicated crossovers, are a very difficult load," Mytek's chief designer, Michal Jurewicz, told me. "Hypex [class-D modules] cannot drive it, the amps collapse, but this Brooklyn Amp does it with ease.”
@addyson 

You mean, like you just did?
Also, that is a paragraph, not an article my friend.

Eric, from what little I've learned (and George will probably help us out here) about Class D, there are modules: ICE, NCore, Pascal architecture, etc. One of the very interesting  and best things about Class D is that those modules can be made modified and made proprietary by engineers. 

E.g. I learned about the Class D "Cherry" amps on Audiocircle a few months back. the Co is the "Digital Amplifier Co", based in PA, and owned and operated by an electrical engineer and software engineer: Tommy O'Brien. And bigger companies do this too to get the best sound at a certain price point. 

Tommy is totally independent, he is the quintessential stay at home genius who prefers to do all his own work, keep it small, be nice and neighborly to all customers. 

https://www.cherryamp.com

[I ordered a Cherry Ultra amp, he builds them one at a time by hand: its a hybrid SS and Class Damp with an 1800w transformer, and  Class D output = 675watts into 4 ohms]
addison:

If your going to copy and paste something from an article, you shouldn’t do just part of it.

Meh.  I included the source, and the rest of the paragraph doesn't really change the quote. If you were my editor and this was a site I was paid to post to I'd really really care. 

E
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elizabetty something something not replying to nonsense, something something. 


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Thanks, I can be very becoming.
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addyson815
If your going to copy and paste something from an article, you shouldn’t do just part of it.
"Duntechs, with their multiple drivers and complicated crossovers, are a very difficult load"
" Hypex [class-D modules] cannot drive it, the amps collapse"
But that’s always been the case with Class-D, get a speaker that has an EPDR load (combined impedance and -phase angle) of <2ohms and they **** themselves. And this kind of this load is in more speakers than what your aware of it’s hardly ever measured or printed.

Cheers George
@1graber2 , if we are getting technical it is a "review", not a paragraph .

@erik_squires, the part you posted was a portion of a paragraph. Now that we have cleared that up.... not sure you would want an editor, as they would suggest edits and you may or may not want to take that advice.

@elizabeth, thank you. I thought the part left out changed things quite a bit too but I guess when one takes the time to read the entire paragraph, article, review or whatever and considers all the information vs. skewing it the way one wants to read it then it isn't as fun for some. Again, thanks. 


Well, I’m sorry, I did not agree when I posted the article, I did not trim it to be scandealous, or click bait. You want to complain, pay me. Otherwise, add to the conversation.

From my point of view, and you may disagree wizabet, either way it is close to libel.

Saying the Hypex doesn’t work with any normal speker is scandalous. The Duntech Sovereigns are specified as being 3 to 4.5 ohms. That is well within what should be the Hypex’s comfort zone.

So we are faced with one of two scenarios:

1 - Mytek is hyping their amp at the cost of Hypex and all the brands who use them like Theta Digital, NAD, etc.
2 - Mytek is right.

There’s not a lot of room in between. Mytek’s Michal Jurewicz essentially just said "Hypex is not a high-end amp"

For the record, I think (but do not know) that Mytek is running an ICEpower amp. Thats cool, that’s what I use in my mains. I’m also a fan of Mytek as I use the Brooklyn as my DAC/pre.

My real point was, I personally am _shocked_ a Mytek rep would say this and let it go to print. He’d better have the juice to back that up. I have never read a menaingful critique of Hypex amps that said they were whimpy. 
BTW, it is NOT OK to brush off Mytek’s criticism as "typical Class-D"

Typical Class D is far better than that. It is a big deal if Mytek is right, or if they are lying. Those are big big claims. And I say this with the full context of the article, not one line or two.

I really expect to see lawsuits threatened over this.

Do any readers have specific experience with Hypex amps and big speakers to confirm or deny Mytek’s claims? Because sadly I do not and I would love to hear a personal experience. 

I mean, all I can say is I like my NAD D 3020, and I love my ICEpower amps, but I'll never have Duntech Sovereigns. :) 
Very confusing thread.  The Stereophile (source) article says:

"Though Mytek ultimately chose an amplifier module from the Danish company Pascal A/S, it's far from an off-the-shelf version. "We use one Pascal," Jurewicz wrote, "but the module is heavily modified.
Read more at https://www.stereophile.com/content/mytek-brooklyn-amp-power-amplifier#44hgh8sJMVVfdyJY.99
"
 
But Erik says he thinks Mytek uses an ICE module; does he have any reason to believe the article is wrong?
what gets me is that when somebody gets called out on a error, they get all butt hurt, but they dont mind calling out others.

"   My real point was, I personally am _shocked_ a Mytek rep would say this and let it go to print. "

I wouldnt worry about it to much.....


cheeg : 

My bad, I _thought_ that while sober I had seen the insides and it looked like an ICEpower module. I stand corrected, and obviously overlooked that in the article.

Thank you for correcting. 

Best,

Erik
addyson :

Well, I don’t own stock and won’t make money either way, but that kind of attack in the press is really not one I am used to.

Anyone have experience comparing Pascal vs. Hypex amps?
The Duntech Sovereigns are specified as being 3 to 4.5 ohms. That is well within what should be the Hypex’s comfort zone.

Not if there's a -50'-60' degree negative phase shift also at 3ohms, then the amp could be looking at nearer 1ohm.

Mytek ultimately chose an amplifier module from the Danish company Pascal

And this could indicate Pascal get them from China and mod them. As are Red Dragon and Rowand Research

http://www.pascal-audio.com/amplifier-modules.html

http://www.theaudiobeat.com/equipment/pics/jeff_rowland_continuum_2_large_inside.jpg

https://www.reddragonaudio.com/products/s500?variant=969867425

https://www.stereo.net.au/forums/uploads/monthly_2017_05/Capture.JPG.eecf146fa0c42ac376beb2799afd581...

Cheers George

Not if there's a -50'-60' degree negative phase shift also at 3ohms, then the amp could be looking at nearer 1ohm.

Not exactly how this works, but yes, large phase shifts mean high currents near zero volts. Hard for most amps. Would be nice if we had impedance graphs for the Duntechs. 
Not exactly how this works, but yes, large phase shifts mean high currents near zero volts. Hard for most amps. Would be nice if we had impedance graphs for the Duntechs.

There is a formula for it, on diyAudio somewhere, but as usual it was in my head while I needed it, but soon sieved out of there in a hurry, like rats on a sinking ship.

As for impedance graphs with -phase layovers, Stereophile is the only one to do this, but they never use the EDPR formula to give the real load the amp sees.

Only one I’ve seen do this is Miller Audio Reasearch Test Labs, when they did 3rd party Lab Report testing for HiFi News and Record Review, like they did on the Wilson Alexia, which managed an EPDR of just 0.9ohm!!!! in the bass.
https://www.absolutesounds.com/pdf/main/press/WA%20Alexia%20HFN%200313-4web.pdf

Cheers George


Not if there's a -50'-60' degree negative phase shift also at 3ohms, then the amp could be looking at nearer 1ohm.

Not exactly how this works, but yes, large phase shifts mean high currents near zero volts. Hard for most amps. Would be nice if we had impedance graphs for the Duntechs.
High current at near 0 volts is a lot easier than high current at higher voltages :) This might be why some of our customers had success with the Sovereigns, and we make OTL amplifiers.

Bruno Putzey is one of the top class D designers in the world and the Hypex modules are extremely competent. I highly doubt that they could not drive the Sovereigns. Now the modules need power, and if someone put them in a box that did not give the modules the power they need, that's another thing altogether! I'd be a bit nervous blaming the performance of the amplifier on its modules until I knew more about how well its power supplies worked!
One of the very interesting and best things about Class D is that those modules can be made modified and made proprietary by engineers.
I'm not so sure about it being possible to modify the modules themselves. I believe that they are pretty fixed.

Perhaps the module makers (Hypex, ICE, TI, etc) could tweak the switching frequency for a company like Mytech to impose a house sound, but Class D is high tech and boutique amp makers don't design semi-conductors. 

Where the boutique amp makers get to play and differentiate themselves is with the case, power supply, outputs, and possibly a pre amp.  
Do any readers have specific experience with Hypex amps and big speakers to confirm or deny Mytek’s claims?
My experience is with Rogue’s Hypex-based Sphinx and Pharaoh. Neither could produce the lowest octave of my Monitor Audio Silver 8s (not the most efficient speakers, but certainly not anywhere near the worst). The same applied with my Epos Epic 2s - fairly efficient speakers. My $300 Yamaha embarrassed those amps when it came to bass.
I'm not so sure about it being possible to modify the modules themselves. I believe that they are pretty fixed.
Definitely possible - Rogue does it.
I own a pair of Hypex Ncore 500 monoblocks and they are mind-blowing good. They drive a pair of 3 way Ryan MCL 3 that also have complex crossovers and aren't the easiest of loads. In my system, they beat quite a few highly regarded amps, some costing 10x, and by a wide margin...

I believe that Rogue uses the cheaper ucd Hypex modules, not the Ncore.
At it's price point, it makes sense. 

I'm not so sure about it being possible to modify the modules themselves. I believe that they are pretty fixed.
Definitely possible - Rogue does it.
Rogue adds a tube input stage to sweeten the sound from the Class D output stage. This is a good example of adding a house sound.

Boutique amp makers are under a lot of pressure to differentiate their products from the module, which is also branded. Ice has bundled a power supply with the module, leaving "amp makers" scrambling to find tweaks for the copywriters to wordsmith. 

Things are changing though. Module makers realize that boutique amp makers want more control so they can impart their house sound. Hypex has a module that they won't sell to DIY.

 Anyway, it's interesting to sit on the sidelines and watch a newer market develop inside of our dinosaur hobby. ;-) 
@addyson815
If your going to copy and paste something from an article, you shouldn’t do just part of it.

There is a perfect refutation of this in Dostoevsky's Crime and Punishment.  I wanted to quote the part but ... Oh come on?? 
Rogue is a poor example of an amplifier. I have little ATCs that Rogue couldn't drive comfortably.
Class D amps remain controversial in high-end circles. I did a lot of reading about them before finally buying one (a used Wyred4Sound ST-500 built around an ICEPower core) to use w/my ATC SCM12 Pros. I was struck by how balkanized much of the commentary was: armed camps w/Class A and AB lovers on one side, and Class D lovers on the other. And the Class D ranks were riven with dissent over the positive/negative attributes of various amp cores (Ncore vs ICEPower vs Pascal). 

I don't have a pair of big speakers w/subs built in to test the Wyred4Sound on. But I can tell you it drives these ATCs extremely well. Among other things, I'm getting the best bass I've ever heard from a 2-way speaker. With a Marchand external/electronic crossover & sub in the system, I don't need anything below 80Hz from the ST-500; but I've done plenty of listening without the sub, and the bass is very fine--impactful & tuneful all the way up through the upper bass. Plus there's none of the etched upper mids or treble one kept hearing about with Class D amps 10-15 yrs ago.

Does that mean I'd use Class D if I had a big, expensive living room system? Maybe, maybe not. But IMO, Class D is definitely "on the table" now as a quality sonic option in various high-end applications.
"Shocking" that hifi folks would argue on-line.....shocking
From a couple of manufacturers I am familiar with (B&O and Hypex), the modules offer two inputs. One fully buffered, and the other low impedance.

The unbuffered and low impedance input allows the opportunity for OEM’s to make their own input stages. From tubes to discrete class A amps, you name it.

Of course, it also matters how many you are buying. If you buy 10,000, I am sure B&O or Hypex can accommodate custom engineering changes. :)

Best,

Erik
I’ve had several audiophiles listen to my system. No one ever said "Gosh that sounds like class D"

If they don’t know what is driving them they just sound like really good amplifiers, with the usual issues of amp to speaker and component matching. 

Best,

E
Mytek is known to have been using strange marketing methods, especially  for a pro originated company. I remember when Brooklyn came out they were advertising features worth "thousands of dollars"- I believe they meant the phono input. In my experience nothing beats
n-core in d-class. Recently I compared the new IcePower AS 1200 with nc500oem and the SQ factor is definitely pointing to n-core.

Nugat, 

They definitely did make a big deal of the quality of the phonograph stage. :) I have heard good things about it, but I have cats. :) 

The NAD I listen to has Hypex derived circuits. I like it, but I can't say I can tell it's better or worse than my ICE modules. I'm not feeding them into anything particularly challenging though. 

Best,

E
I also have not (knowingly) heard a Pascal based amp either. Anyone who wishes to send me a pair for evaluation... :) 

There are definitely some fans of those modules too. 

Best,

E
Only one I’ve seen do this is Miller Audio Reasearch Test Labs, when they did 3rd party Lab Report testing for HiFi News and Record Review, like they did on the Wilson Alexia, which managed an EPDR of just 0.9ohm!!!! in the bass.
https://www.absolutesounds.com/pdf/main/press/WA%20Alexia%20HFN%200313-4web.pdf

Cheers George
Ha George, My Watt 3's went one better  0.75 Ohm!

Class D seems to work better than Class AB in Power regeneration Products though.

team212
Class D will continue to evolve and eventually overtake SS and tube ... but this is years down the road ... until everyone over 50 yo has died off ... lol.

Seriously, the Class D are amazing these days compared to even 3 years ago.
I dont understand how anyone can just write off Class D altogether? The dude quoted above ... hasn’t heard high end Class D, eg Merrill amps.

But Eric, I have never heard anyone c/o the Hypex NCORE modules. Never. And they only get better, with better power supplies and support circuit.

And also, to offer an example, I do have a Hypex UCD 400w module that drives a 12" woofer in my Zu Audio Undertone sub. Its a monster. I live in CA and it makes me think I'm undergoing a earthquake.

Last, The Red Dragons have found homes, e.g Clayton Shaw of Spatial speakers used them at trade shows. And the other ICE module mentioned above, I currently own a Bel Canto Ref500s Class D amp. And it still drives my Dynaudios very well (Dyns are known to need and sound best with high power)
Seriously, the Class D are amazing these days compared to even 3 years ago.
This is quite possibly true, however it is hilarious that people have been saying this about Class D for the last 20 years. 
I have read the Stereophile review.
Apparently Mytek built those amps specifically to power their Duntechs.
Those speakers are a 25 years old technology with passive first order crossovers. A strange choice for a pro studio. The JA measurements of the Mytek amps give "respectable" figures. But the amps cannot be measured properly at 2 ohm, as they go into protection modes. So, low impedance performance is not an issue here. The Pascals strong side is their potential brute force, hence the 300wpc (continuous hopefully) metric. They perform nicely with subs, not so in the mids and highs. Ncores can reliably deliver 100 wpc continuous and 700 wpc peak. The heat dissipation becomes a problem. But when used in active architecture, n-cores are unbeatable on all counts. All in all, Mytek is a peculiar amp for peculiar speakers.
Nugat,

That is weird. 1st order crossovers tend to create relatively benign loads as well.

I’m not sure where you got 100 watts for which Ncore though. The modules are available for OEM’s in the 400 to 1200 watt per channel range.

Best,

E
N-core   continuous power output is thermally limited (like any other amp's). You get those figures in the OEM manuals. Currently the top OEM  n-core is nc500OEM. When you pair it with SMPS 1200/700 you might get the PEAK performance of 700wpc.  N-cores assume that 100wpc continuous  is deadly enough for anybody's ears in  a typical residential room . And rightly so. The assumed crest factor of 5-7x gives peaks of 700wpc which is sufficient for most transients.  Hypex is one of the very few companies which are  open about what the real amp power output is . The continuous power output (RMS power is a misnomer) should be tested with standards at least like IEC 60268-5. 
@nugat 

I mean this sincerely: Are you just making up random numbers??


Those numbers are on page 5 of NC500OEM datasheet. Go to hypex.nl.
Overtemperature is indicated as 85 deg Celsius (page 4)
All these class D companies utilize modules from several main suppliers which they modify to their own tastes...   Yet, NuPrime manufactures their own modules and is the best Class D I have heard with the NuPrime ST-10.   And, that is not even their best.  People overlook this company not realizing they stirred a lot on interest in Class D when they were NuForce, now NuPrime.
@nugat

The website is incomplete, and misses the nc1200 :

https://www.stereophile.com/content/theta-digital-prometheus-monoblock-power-amplifier

And... why does 85C matter? All amplifiers are thermally limited. There’s no evidence that the Hypex modules cannot handle their rated power for extended periods of time if properly cooled.

https://www.stereophile.com/content/theta-digital-prometheus-monoblock-power-amplifier-measurements

The same is true for ICEpower modules. Stick them in a closed wooden box and they are not going to be able to perform to their spec as well as in fully heat dissipating enclosures.

On the other hand, in a normal enclosure, I defy you to get those amps anywhere near 85C/185F
All these class D companies utilize modules from several main suppliers which they modify to their own tastes... Yet, NuPrime manufactures their own modules and is the best Class D I have heard with the NuPrime ST-10. And, that is not even their best. People overlook this company not realizing they stirred a lot on interest in Class D when they were NuForce, now NuPrime.

NuPrime does not manufacture their own modules. When pressed on who their supplier for modules was, they refused to answer. That does not mean that they aren't actively involved with the engineering types of decisions. It just means that they are not a semi-conductor company. 
@erik_squires
NC1200 is for select customers only, and has been mostly replaced by NC500. They have the same power specs for 4 and 8ohms, the 2 ohm power output rating is higher for nc1200 .Datasheets can be easily googled. Bruno Putzeys designed all n-cores with "the same sonic signature", which did not help the NC1200 "high-end" priced unit.
Icepower 1200AS has a peak power rating of 1250wpc (4 ohm, 1kHz, THD1%) however "continuous output power without thermal shutdown" is 280 wpc for the same signal (page 11 of the manual). The test is conducted with the module mounted on an additional heatsink with Rth=0.8 K/W, free airflow (page 11).
Let’s keep in mind 1kHz sinewave is not music. AES/IEC recommend pink noise over a decade (IEC 40hz-5kHz) with a crest factor of 6dB to imitate a typical musical program.




Helomech: My experience is with Rogue’s Hypex-based Sphinx and Pharaoh. Neither could produce the lowest octave of my Monitor Audio Silver 8s (not the most efficient speakers, but certainly not anywhere near the worst). The same applied with my Epos Epic 2s - fairly efficient speakers. My $300 Yamaha embarrassed those amps when it came to bass.

I'd like to share a contrasting viewpoint to Helomech's.  I've had several amps driving my Magnepan 1.6s/1.7s over the years.  Of course, these speakers demand lots of current from an amp.  I had never given much attention to Class D amps, as most that I had previously heard sounded somewhat sterile to my ear.  Then I dropped a Rogue Sphinx into my system and my jaw dropped.  It was not only musical, but had excellent dynamics and power.  This was especially true in the bass.  It was difficult for me to believe that such a budget amp could mate so well with the Maggies.  I attribute some of the musical nature of this amp to the tube preamp section.  Some of the dynamic power may be due to its hefty linear (as opposed to switching) power supply.  In any case, it's an amp worth auditioning even if your budget can afford more.  BTW - I also tried the Pharaoh in my system and found it wanting.  There's something special about the Sphinx, at least in my system's configuration.  It's certainly not lacking power, including in the bass region. The folks at Rogue are great to deal with as well. 

Let me add that I've always respected Yamaha products.  Great value for the money.  Back in the VHS days, I would only buy Yamaha players.  More recently I purchased a Yamaha sound bar for my family room's Sony TV.  However, I'd be somewhat shocked if one of their $300 amps can best the Sphinx.  A model number would be helpful...  

Best to all - Michael 

Pascal amps were a spin-off from IcePower as an OEM/Pro division. The conceptual design and the technology were very similar, only adapted to the Pro Applications.
The concept is indeed inferior to Hypex (Bruno Putzeys) as well as the sound quality.
It needs to be tweaked to sound better. Hypex (nCore in particular) is indeed a circuit better adapted to complex loads so the statement that caused a lot of comments here makes no sense and seems to be a desperate sales pitch fallacy targeted at a technically superior competitive concept. Not uncommon in "High-End" where the value-for-money factor is typically poor.
I have used extensively and tested a Pascal-based power amplifier that had been tweaked with a valve-based stage driving the modulator directly.
The tweak is possible with Pascal, not possible with Hypex (Being a closed design) and that is why companies like Mytek take Pascal, make (slight?) modifications and brag about nonexistent supremacies.
Try both and you'll be able to experience the differences. Use your own mind and your own ears. As simple as that.
I would also look at the Orchard Audio as Leonid (The designer) does not recycle someone else's IP but creates a unique circuit using new GaN devices. According to my humble opinion, an original approach well worth auditioning.