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
Since I am sure in moments all sorts of posts will appear to talk about how terrible sounding Class D amps I want to say this:
I've been listening to ICEpower ASP modules for years and they are really wonderful. There is no hint of anything they used to talk about Class D. They are not hard, they are not noisy, they are not compressed or clinical. They are very warm sounding, perfectly natural sounding amps which I cannot tell apart from linear amplifiers. 
If you feel like dropping $1k to build yourself really nice stereo pair and listen for yourself, I encourage you to. I also don't mind if you like something else instead.
Post removed 

Or, you will have people like myself praising you Erik for continuing to lead the charge!

Anytime you have a hobby like this one going through such a huge paradigm shift it brings out the emotions on both sides and more. Many of us who have secretly been exploring Class D and simplicity are finding soundstage and tonal bliss. It takes a slight adjustment to go from mega dollar systems to the more balanced approach that happens to cost much less. Keep in mind though that places like Agon are going to be one of the last stand forums. It's great watching Agon make the transition from old to new or more money to less or high mass to low mass and other comparisons.

I'm glad your being diligent and we want you to know your far from alone. Most may not post on the paradigm shift and many will troll the heck out of you, but these times they are a changing, and there's really no stopping progression wants it gets rolling like a rolling stone.

Michael Green

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).
But it's not just the modules. The input and output stages matter too.
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.
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

@stevecham  
 
You may not be a measurement man, but the kit has been measured and it excellent for its price.
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.
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.

Erik, I want to thank you for this thread; I will investigate.
@marqmike

I have a class b amplifier



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

Best,
E
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


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...
ICEPower and Hypex are some of the best amps on the planet, only behind Devialet. But this is absolutely not something most members of this forum should attemp to build (judging by the consistent daily posted nonsense). SMPS voltages will kill you proper. 
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

     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 

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.
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


invictus005

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. I get accused of my F5 being easy to build. I at least stuffed boards and stuck probes into the thing. 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. That makes a Pass ACA look like rocket science, and those things are made for 12 year olds to build. 
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

That's not my understanding of how an SMPS works at all. A simple SMPS converts mains voltage to DC and filters it a little. DC is then pipes into some kind of transistors, typically a FET, which is driven by an IC. The output side is coupled to the input side through a small transformer. Feedback from the output is fed back to the switching IC for overload protection and switching frequency moderation to maintain the output voltage. The output is filtered according to noise floor requirements. Unless the output demands high voltages, there's no reason for there to be voltages higher than the rectified mains voltage. No SMPS has reservoir capacitance like a big linear supply does. I wouldn't want to take 47uF at 150V, but I'd choose that over 120,000uF at 32V. 

People survive lightning strikes and thousands of volts in the form of common static discharge all the time. There's no arbitrary rules about volts or amp. A few milliamps can kill you with enough volts and a few volts can kill you with enough amps. That's what makes caps so dangerous. In solid state gear the pack low voltage at huge capacity, while tube gear pack very high voltage at relatively low capacity. Both will make your day pretty bad. 
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.

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
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.
@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

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.

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. 
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

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
@kosst_amojan your post lacks basic SMPS knowledge. What you write is wreckless, dangerous, and irresponsible. 
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
Hey @evelyn1

Let us know what you think!

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?
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


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
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?
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
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?
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
  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

     

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.

Post removed 
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

     
 

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 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
Do the NC400 Hypex kits come with two mono amps or do you have to buy two at € 650 for stereo?

Post removed 
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?
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.