How to DIY yourself very nice Class D monoblocks


If you want to know what the hoopla is about Class D and want to put together a very nice sounding kit I have a starter recommendation for you.

Go to Parts Express and search for "ICEPower ASP"
Next, look online for Ghent Audio. They make many sets of cases.

You'll need a high power soldering iron, and screw skills.
Between those two, you can put together a very nice monoblock for around $500 a piece.

I highly recommend both. I have no financial interest in either. 
You may need wiring kits, so make sure to order appropriately.
erik_squires
I too have built the hypex N core mono’s. Very easy for a first time dyi project that was fun. The units took about 5 hours total to build and guess what? They sound awesome, replaced my beloved pass lab 150.5. Then bought a EVS 1200 second hand and it sounds even better which replaced another older Bryston 14 b which I moved over to sub amp duty. Love the small footprint absolutely silent dead background and effortless powerful sound. Now have a much cooler audio cabinet and probably lower power bill🎉😆. Glad I took a chance on class d. Todd
Sorry @recluse but I recommend the DIYaudio website as a great place for electronics noobs to get help and advice.

Best,

Erik
Erik,
Thanks for the thread. Is there a good source on how to assemble these properly, once parts are acquired?
..Parts express ice asp modules and ghent enclosures.

Thanks
Sorry, George, I was comparing similar amps to each other.  What you linked to is not even close and then you mentioned something that doesn't even exist yet. 

I’d be more inclined to have a go at these, USA made sold and backed.
https://classdaudio.com/amplifier-kits.html

Proper linear power supplies with Toroidal transformers, not noisy switch mode ones.
And these are far less costly than the Euro alternatives, also come in kit or assembled.

And these guys are soon to release a GaN technology Class-D, they know where the progression of Class-D sound quality is coming from

Cheers George

Check out this Nord amp.  It is the exact same price in USD as the Hypex NC400 kit, but it comes with the NC500 module, an input buffer, a bigger power supply, and it's already assembled.

https://www.nordacoustics.co.uk/product-page/nord-one-nc500dmst-3

If you buy the stereo version, it's actually cheaper than two Hypex mono kits.
The latest Icepower modules (IceEdge 1200AS1 and AS2) are not sold directly to end users but to OEMs only. They are way, way better sounding than any other Icepower module......and even better than Ncore NC400 and NC500 modules.

Which exact amplifiers have you compared to come to this conclusion?
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Do the NC400 Hypex kits come with two mono amps or do you have to buy two at € 650 for stereo?

Hi Michael,
  I've been following these threads concerning class D amplification for some time now. I've seen your posts on a regular basis along with some others and it has been quite interesting. I guess that if an amplifier does nothing more than accurately increasing a signal that it receives then there's not much more to discuss about amplifiers. If this amplifier exists and you don't like what you're hearing then the real problem lies elsewhere. No more discussion about how an amplifier sounds. Either it's doing something to the input signal ( besides increasing it) or it's not. I'm talking about what's in the parameters of human hearing and not some frequency way beyond. I took the plunge and tried class D for myself and came out a happy customer. Others can say what you want but I actually tried it for myself and don't regret it. It's way better than what I had. Also, I removed the 130 lb. Krell amp from my system without hurting my back so things are going well. There was an occasion when in the process of sending the Krell amp back to CT that I threw my back out. It was about a month before I was back to normal. I've had that amp for nineteen years so it's definitely time to move on. It was the mainstay in my setup for many years and I really did appreciate it. Our cars no longer use carburetors and soon stereos will no longer be using some of types of systems that are dominate today. It's just going to happen whether we like it or not. Thanks for your reply and enjoy the music and changes. Sincerely, 

             Frank

Hi Frank

I'm glad you posted. The more people post about their conversions from old to new the faster the hobby will get out of that overbuilt over priced mentality. It's very interesting to watch. If there has ever been an obvious overnight revelation in HEA this is it. This will help the hobby redefine itself moving toward a much lower mass approach to system designing.

I think the HEA shows are in for some major changes in the next couple of years.

enjoy

Michael 

Hi All,
   After some minor problems with the purchase process of Hypex N400 kits, I was pleased to have it arrive yesterday at about 5:00 PM. After eating dinner I decided to assemble the kits and see how much I could get done. By 9:00 PM the kits were fully assembled and ready for action. At this hour I'm usually done for the day and already sleeping but I had to try them out. The big test for me was whether these amps would sound better than the Krell FPB300 in my system. I originally was  going to give the amps a week of break-in time and then report my experiences. They sounded so good that I didn't want to go to bed. They clearly had more detail than the Krell. It was very difficult to switch from one type of music to another because it all sounded so good. The Krell is no slouch but these little mono blocks are better. They really pair nicely with PBN 741 speaker kit. The total cost came to $1612.16 USD. Rudy van Til of Hypex DIY customer service was very helpful. Once payment was confirmed the package went from The Netherlands to NJ in six days. I had to use Paypal to make the transaction work. The fun part of this hobby for me besides the listening is putting together a system in a frugal sort of way. The Hypex N400 kit is a very pleasant surprise after years of seeing the incredibly high prices of top rated amps ( and other equipment ). My stereo system is now complete after two years of upgrading. I was expecting to spend $5000 or more for a high quality used amp. I now have extra money for vacation. Netherlands perhaps?
      Cheers, Frank

     
 
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I hope this post can save people some time and money.

The Icepower ASP modules being sold by Parts Express are very old technology. I sold mono blocks with the 500 watt modules for $2000 the pair in 2006. Here is a review of them.

http://10audio.com/evs_500m.htm

The latest Icepower modules (IceEdge 1200AS1 and AS2) are not sold directly to end users but to OEMs only. They are way, way better sounding than any other Icepower module......and even better than Ncore NC400 and NC500 modules. You can buy a complete stereo amp from Europe delivered for a hair over $1000.

https://www.rougeaudiodesign.com/studio-n-10 Click on the British flag on the top right for English version.

Here is a comparison between stock IceEdge and NC500 Nord amps.....both were mono amps:

https://www.audiocircle.com/index.php?topic=154910.msg1660700#msg1660700

Look for reply #97.....debit.g

Here is a comparison of a stock stereo IceEdge to modified mono NC400s.

https://www.audiocircle.com/index.php?topic=154910.500

Look for reply #509.....mikeeastman

You might have to log into Audiocircle to read these last two posts as they are in the Intergalactic wastebin files.

  ketchup,

      I know you can purchase completed kit amps that contain two HypexNC400 class D modules in each mono block from James Romeyn Music andAudio, LLC in Utah.  I believe his dual mono versions cost about $3K/pair and are powered by the largest Hypex NC1200 switch mode power supply.   
     I've never auditioned the dual monos but he claims the dual mono versions sound better than the regular monos. 
      Several years ago, I talked to James Romeyn at length about having him build a custom pair of mono blocks for me using a single class D Abletec ALC1000-1300 module per case. Abletec has since been purchased by Anaview,another Scandinavian class D module producer and competitor to Hypex and other producers.  Anaview and Pascal class D modules have alternative designs that incorporate power supplies into their modules rather than as separate parts/boards.
     James was very knowledgeable about class D in general and took the time with me in explaining the specific differences between building amps using his Hypex and Ice based modules and other competing modules.
     I think he'll likely be equally helpful in answering your questions.  Here's a link to his website:
http://jamesromeyn.com/product/hypex-professional-build-service/#tab-description
     
Tim

     

Sorry @Ketchup, I can't imagine the need for bridging those amps, but I do see you increasing your complexity dramatically.

I'm not sure what the impedance would be, but you can find it from their data sheets. 
I'd like to strongly suggest to you that you get a stereo pair, and see if you feel there's any need at all to do more.

Best,

E
I’m not really interested in active biamping yet. I just learned that the NC400 modules are bridgeable, so it’s possible to use two modules per channel and have double the power. Would the input impedance of two bridged modules also have an input impedance of 4k ohms?
Hi @ketchup
Not really, but the impedance would drop to 4k.

Most solid state pre amps would have no issues with this at all, but some tube may.

However, maybe what you really want to do is active biamp? Hypex sells active crossover modules as well.

Best,
E
Thanks, george and erik.
Let's say you wanted to build two mono amps with NC400 modules, but you wanted to put two NC400 modules in each mono chassis so one would drive the bass panel and the other would drive the midrange/tweeter.  Is it possible to split the input at the mono amp so the signal goes to both NC400 modules?  Are there any possible downsides in doing so?
I think it’s around 7-8K ohms. My preamp’s output impedance is 200 ohms. That’s not good, right?
Your good with that, but these amp manufacturers that insist on inputs that low need to be beaten around the head, as no passives or most tube actives will drive these silly low input impedance’s.
There was a sort of unspoken standard for a while which was 47kohm or higher. I think 100kohm should be made the standard.
Hell Rogue Audio on most of their poweramps are 1megohm!!!

Cheers George
What are you guys doing to get around the low input impedance of the ASP modules? I think it’s around 7-8K ohms. My preamp’s output impedance is 200 ohms. That's not good, right?

Hi @Ketchup,
200 should be fine!! It's usually recommended that there be a 10:1 ratio, so you'd have more than enough.

Best,
E


What are you guys doing to get around the low input impedance of the ASP modules? I think it’s around 7-8K ohms. My preamp’s output impedance is 200 ohms. That's not good, right?
Thanks to all on all the posts here. After doing some researching and reading the posts above, I pulled the trigger on Hypex nCore NC400 mono kit (x2). I'm not an electronic engineer but I figured that if Bel Canto went with Hypex on their recents amps, then they are probably better. The pair of kits include everything, require no soldering, and cost $1540.00 in US dollars including overseas shipping. I can afford taking a chance at this price and have a feeling I made a good decision. I'll return here when I get this installed and let you know how it compares to Krell FPB300. Thanx again, Frank
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George,

Your link to Gan-fet is from 2014 and Purely Emotional Audio is an offshoot of classdaudio. They have yet to produce anything using that name.



Here is a an email back to me from the US company "ClassDAudio" regarding the use of the new GaN Fet technology in any of their completed amps or very well priced Class-D kits they make, that use linear power supplies!!  I've sent one to PureAudio also.
https://classdaudio.com/amplifier-kits.html

"Hi George,

These will not be available in kits. These amps are complex and expensive to manufacture. We’re hoping to have complete amps ready maybe in about a month. We’re still finishing case design. Tom"


Cheers George
Hi All,
  Has anyone done any comparisons between the Bel Canto e.One REF 600 M and the IcePower ASP kit. I'm currently using a Krell FPB 300 with a PBN 741 speaker kit and a newer model amp is the last item on my improvement list. It would be great if Stereophile did some reviews on some of the kits.

Thanx,                                                                                                                     Frank
Erik, TI has quite a bit of info on their website with plots for the whole chip family.  Interesting threads about tpa3251/tpa3255 on diyaudio as well.  The TI module is plug and play essentially and the sound is refined with some serious low end grunt.  Best with an active preamp. 

Erik,

Looks like 500K switching to me.  The oscillator is in the megs.....not the PWM frequency.....maybe I don't know nothin.

George,

Your link to Gan-fet is from 2014 and Purely Emotional Audio is an offshoot of classdaudio.  They have yet to produce anything using that name.

@rotarius

That is an interesting find! 300W/channel, and uses a very high (relatively) 2.1 MHz switching frequency!

It would be really nice to see frequency vs. phase plots for these amps.

Best,

E
My TI tpa3255 evaluation board is the best solid state amp I have ever had.  My references for ss amps are mid-level pieces I have owned such as Belles 150a, Bryston 4BST, B&K, Aragon 8002, NAD units and such.

Do you want to stay away from Chinese or Euro stuff?

Here’s quality USA made Class-D audio kits, these look to be great value with some big wattage’s and they use linear power supplies!!!, "said" to sound as good as APL’s Alex Peychev’s $150k tube amp.
http://classdaudio.com/amplifier-kits.html

It also looks like they maybe be producing GaN fet technology kits soon, as they are linked to the GaN site along with Purely Emotional Audio
http://gan-fet.com/2014/02/13/desert-rocks/

Cheers George
Well, that certainly IS what is claimed. Interestingly, and sadly, none of the reviews I’ve found explain it. I know of no class B circuit which allows an amplifier to operate without significant distortion through the zero V crossing point, which is why I said earlier it couldn’t be. If I was reviewing such an amp I would have made it a point to explain this.
FWIW Electro Voice sold a class B with low distortion back in the 1950s. To avoid spikes due to collapse of the magnetic field in the output transformer that transformer was not exposed to DC- just audio. So the amp didn’t have any crossover artifacts. But its tricky and expensive to do, so the idea didn’t catch on.


Nice thread BTW.
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I seriously doubt there's an SMPS in any audio amplifier that's as life threatening as the big linear supplies resting in the heart of any class A amp


What's life threatening is high voltages. It only takes a few milliamps to stop your heart. I believe that switching power supplies have much higher peak voltages than linear amps of the same power. In the 200-300V range. The amplifier portion itself runs lower. This is all quite fuzzy and old knowledge so I can be wrong.


That thing takes nothing more than screwing boards into a box and running wires to a power switch and signal posts. I can't imagine it being more simple than that.

And this is also true. Assembly is dead simple. Keep your fingers and tools out of the way when it's on, and be aware the caps can maintain a very high voltage even after they are off.

Best,
E

Post removed 
Belles reference 150 v2 class ’B’ amp


Well, that certainly IS what is claimed. Interestingly, and sadly, none of the reviews I’ve found explain it. I know of no class B circuit which allows an amplifier to operate without significant distortion through the zero V crossing point, which is why I said earlier it couldn’t be. If I was reviewing such an amp I would have made it a point to explain this.

I don’t know everything, and I’m not an EE, but this is now a very curious thing to me.
This is certainly the first Class B amplifier I've heard of with high end cred.

Best,
E


Erik
Belles reference 150 v2 class ’B’ amp
David has started with a clean slate for the Reference series, and this amplifier bears little resemblance to its ancestors. The 150A Reference V2 is a Class B design that provides 125 watts per channel into an 8 ohm load,. Yup I checked again it is a class ’B’ amp. David has taken the Class B circuit used in the original 150 Reference amplifier, and has craftily applied his engineering savvy in order to tease a higher level of sound quality out of an already excellent design. I keep solid-state gear on all the time, and the Class B circuit design means that the amplifier is not an energy hog.   Fantastic amp. I do not think to many people can pull this off. Very good designer.

     Good thread Erik.  

    Building your own class D amps is an excellent way to get hi-end sound quality at an affordable price.  The performance levels of the more recent class D modules are, in my opinion, outstanding and this technology has broken the mold on how to attain high quality sound from a home audio system.
     Previously, the only known and accepted method consisted of using large, heavy and expensive traditional class A solid-state or tube amps or ss class AB amps to drive the often very demanding requirements of the various high quality home speakers typically used.  
     Class D amps have broken, smashed?, the traditional mold of how to attain excellent home audio quality for both home theater and music.  Compared to traditional amps, they're smaller, lighter, electrically more efficient, run cooler, less expensive and I believe sound just as good or better.
     What's not to like, right?  I've been using them in my system for about 4 yrs now and can't think of anything. Class D amps are really wonderful.
     So, I completely agree with Erik's recommendation of building class D module based amps.  You can build your own, have them built for you or buy completed amps using these modules under various brand names.
Enjoy,
 Tim 

ICEPower and Hypex are some of the best amps on the planet,



Well, I wouldn't go THAT far either. I haven't heard everything, and I haven't had a chance to compare them all with all sorts of speakers.

I am however very very pleased with what I have.

But this is absolutely not something most members of this forum should attemp to build (judging by the consistent daily posted nonsense) 

The kits are super easy to assemble. The IcePower units especially.

Best,
E
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mzk.... I’m into measurements and listening equally. I’m into it all and have been for many years. I’ve even built Marshall 45, 50 and 100 watt tube heads for local bands that sound killer. At some point I might just get interested in DIYing some Class D monoblocks. Lots are happening in this space, all for the good of audio enthusiasts. Enjoying my PS Audio M700 monblocks too, immensely. Just saying...
But it's not just the modules. The input and output stages matter too.


They do!

Many Class D module makers provide the option to separate the input from the rest of the amp, providing a very low impedance interface. The vendor is then responsible for making their own. This could be tubed for instance.

However, I'm not here to sell that idea. All I am here to sell you is that you can build very nice sounding monoblocks inexpensively, and if you are curious about Class D, and want to tinker, here you go.

Both ICEPower and Hypex provide it all.

The ASP modules have build in power supplies. The Hypex need you to purchase that separately.

Best,
E


@marqmike

I have a class b amplifier



I sincerely doubt that is true! :) It is A or AB.

Best,
E
I purchased a Wyred 4 Sound  St 1000 mk2 to drive Magnepan1.7s.   Excellent. I ran it with the preamp section of my McIntosh MA6900 and thought wow the Maggie’s do like lots of juice.
Class D is great and will interest many more young audiophiles.
Thanks Erik. Nice thread. I have to say I  am interested for the first time in class d amps because of the thread on a gan device amplifiers. I have a class b amplifier and it is an excellent amplifier.
@stevecham  
 
You may not be a measurement man, but the kit has been measured and it excellent for its price.
The Hypex kit is more expensive (<$1500 for a pair of monoblocks) but better quality amps and it’s so easy, no soldering needed (first gen kit did, but not current gen).

Allegedly better. Anyone who would like me to review and compare, please send me a pair... ;)

Yes, if you are interested in NCore, look for Hypex Shop

Seems that I just saw a little kit from Pete Millet for a D amp. Might have been a mono block, not sure. Really like his stuff though.