Hi,
Aside form the marketing junk it doesn't sound too bad.
http://www.nuforce.com/index.html
http://v3.espacenet.com/origdoc?DB=EPODOC&IDX=US6381154&F=0&QPN=US6381154
Couple other patents to be found of theirs but... they seem nearly identical.
Cheers,
Chris
Aside form the marketing junk it doesn't sound too bad.
http://www.nuforce.com/index.html
http://v3.espacenet.com/origdoc?DB=EPODOC&IDX=US6381154&F=0&QPN=US6381154
Couple other patents to be found of theirs but... they seem nearly identical.
Cheers,
Chris
Had a quick look, for the apparent quality the prices look pretty good for a finished amp.
Anyone seen or heard them?
Interesting comment in their "about Us" page
" In addition to our ground breaking Analog Switching Amplifier (based on Class D circuit topologies with NPhysics patented and patent pending modulation techniques), we look forward to introduce our ultra-efficient, high power (1000W and beyond) Class N Audio Amplifier in 2005."
Anyone seen or heard them?
Interesting comment in their "about Us" page
" In addition to our ground breaking Analog Switching Amplifier (based on Class D circuit topologies with NPhysics patented and patent pending modulation techniques), we look forward to introduce our ultra-efficient, high power (1000W and beyond) Class N Audio Amplifier in 2005."
Hi Chris,
I beleive this is what you are looking for. It has been some time since I looked at the patent application, but as far as I can remember it is a variant of ampliverter design using single ended front end instead of the more usual push pull one.
BTW, Nphysics is parent company of Nuforce
Best regards,
Jaka Racman
I beleive this is what you are looking for. It has been some time since I looked at the patent application, but as far as I can remember it is a variant of ampliverter design using single ended front end instead of the more usual push pull one.
BTW, Nphysics is parent company of Nuforce
Best regards,
Jaka Racman
Hi,
after looking at their site, it seems that they are not using ampliverter design yet, but switching amplifier with SMPS.
They use post filter feedback and control that is not unlike that of UcD.
Measurement results look respectable. See atached picture.
Best regards,
Jaka Racman
after looking at their site, it seems that they are not using ampliverter design yet, but switching amplifier with SMPS.
They use post filter feedback and control that is not unlike that of UcD.
Measurement results look respectable. See atached picture.
Best regards,
Jaka Racman
Attachments
Hello,
Wytco0, I think the cost is reasonable because of their SMPS usage. The prices are on par with some of their competition but they don't yet seem to be meeting anywhere near the power levels of their competition.
I missed that part about comming out with a >2000W amp. We'll believe that when we see it won't we? They dont' seem to even have a 200W one yet, so that's quite the leap. I hope they don't mean ten 200W channels @PMPO.
Hi Jaka,
Yeah I've seen they're somehow affiliated with Nphysics as well, the topology seems a little different though, but I think they work the same way. These jokers seem to be refering to it as "Class N" as well.... 🙄
The patent I linked to should be one of the older ones for what they're selling on their website.
This link seems stuffed up now but you should be able to a find more of their recent ones here, they're very similar but perhaps only go into more detail.
http://v3.espacenet.com/results?sf=...AB=&PN=&AP=&PR=&PD=&PA=&IN=&EC=&IC=&=&=&=&=&=
Yeah that graph looks great, they said ruler flat response up to 150kHz, would be interesting to hear.
Best Regards,
Chris
Wytco0, I think the cost is reasonable because of their SMPS usage. The prices are on par with some of their competition but they don't yet seem to be meeting anywhere near the power levels of their competition.
I missed that part about comming out with a >2000W amp. We'll believe that when we see it won't we? They dont' seem to even have a 200W one yet, so that's quite the leap. I hope they don't mean ten 200W channels @PMPO.
Hi Jaka,
Yeah I've seen they're somehow affiliated with Nphysics as well, the topology seems a little different though, but I think they work the same way. These jokers seem to be refering to it as "Class N" as well.... 🙄
The patent I linked to should be one of the older ones for what they're selling on their website.
This link seems stuffed up now but you should be able to a find more of their recent ones here, they're very similar but perhaps only go into more detail.
http://v3.espacenet.com/results?sf=...AB=&PN=&AP=&PR=&PD=&PA=&IN=&EC=&IC=&=&=&=&=&=
Yeah that graph looks great, they said ruler flat response up to 150kHz, would be interesting to hear.
Best Regards,
Chris
The single cycle control is simply fantastic!
The patent claims to give a 'substantially constant switching frequency', and also a fixed fall-back cycle period. (Hence the single cycle control). Assuming it can process a signal ...
it must modulate the signal on the other (non fixed) half of the cycle, this means it can actually change the cycle time, while at the same time keeping a 'substantially constant switching frequency'. These guys are tough!!
Finally someone broke the time barrier! 😀
The patent claims to give a 'substantially constant switching frequency', and also a fixed fall-back cycle period. (Hence the single cycle control). Assuming it can process a signal ...
it must modulate the signal on the other (non fixed) half of the cycle, this means it can actually change the cycle time, while at the same time keeping a 'substantially constant switching frequency'. These guys are tough!!

Finally someone broke the time barrier! 😀
The Nuforce amps are also "famous" for their 0 degree phase shift over the total bandwidth, something other class-d designs have trouble with.
Don't know if this phase shift is very audible though?
Don't know if this phase shift is very audible though?
Lars Clausen said:
Finally someone broke the time barrier! 😀
Damn, just today I was discussing having only one speaker that morphed dimensions through time for a true surround system.
Hmmmmmmmm would that be digital or analog?
😀
Hi
as I mentioned on another post
I was very impressed by the Nuforce amps
compared to the BelCanto T amps.
They seem to have more depth and realism.
We were listening to a Bel Canto front end with
Raven 1 and Thiel Ceramic speakers. The size of the
amp and its amazing lack of mass were also very
endearing. Hope to hear them again soon. Sadly OEM
customers only for doing your own 6 channel version!
Regards
AnthonyPT
as I mentioned on another post
I was very impressed by the Nuforce amps
compared to the BelCanto T amps.
They seem to have more depth and realism.
We were listening to a Bel Canto front end with
Raven 1 and Thiel Ceramic speakers. The size of the
amp and its amazing lack of mass were also very
endearing. Hope to hear them again soon. Sadly OEM
customers only for doing your own 6 channel version!
Regards
AnthonyPT
I'd love to see different modern class-d amps face off against eachother...
Anyone who listens to a nice class-d (in my case UCD) is always very much impressed because of the "different" sound compared to class AB.
However, we all seem to lack to compare the different class-d's - maybe because we're all very happy with what we have.
If it is T-amps, UCD, nuforce or ICE, the words keep coming back... fast attack, great dynamics, easy handling of all kinds of speakers... it's a huge step forward.
Maybe the difference between the different class-d's is not (so) important anymore because the quality we're dealing with now has made a quantum leap.
Anyone who listens to a nice class-d (in my case UCD) is always very much impressed because of the "different" sound compared to class AB.
However, we all seem to lack to compare the different class-d's - maybe because we're all very happy with what we have.
If it is T-amps, UCD, nuforce or ICE, the words keep coming back... fast attack, great dynamics, easy handling of all kinds of speakers... it's a huge step forward.
Maybe the difference between the different class-d's is not (so) important anymore because the quality we're dealing with now has made a quantum leap.
Wait for the fight between Nuforce and UcD...
Jaka Racman said:Hi,
after looking at their site, it seems that they are not using ampliverter design yet, but switching amplifier with SMPS.
They use post filter feedback and control that is not unlike that of UcD.
Measurement results look respectable. See atached picture.
Best regards,
Jaka Racman
NuForce is also known for their unstability. I have seen a handfull of NuForce amps after a total burn out. Not caused by heavy load... Simply caused by no load.
I heard about a fail rate of around 5-10%...
Very impressing and really worth a patent.
I heard about a fail rate of around 5-10%...

Very impressing and really worth a patent.

There is talk about the failure rate on the 6moons website.
The first batches were in fact betatested by the users...
Disconnecting the load when the amp is on is a no-no for the Nuforce.
Soundwise however, it's nothing but praise for the machine. They probably have a good circuit design but bad lay-out/parts/stability.
Quote from sixmoons audioreviews:
They should give hypex a call, lol 😀
The first batches were in fact betatested by the users...
Disconnecting the load when the amp is on is a no-no for the Nuforce.
Soundwise however, it's nothing but praise for the machine. They probably have a good circuit design but bad lay-out/parts/stability.
Quote from sixmoons audioreviews:
Jason Lim assured me that "we have more than 600 units of Ref 8s and 9s in more than 20 countries and there have been failures. The failure rate is about 6% including problems during the initial launch of products from March to June
They should give hypex a call, lol 😀
They haven't heard of Hypex.
Actually if they had a good circuit design they wouldnt' have those problems, best parts in the world can't withstand abuse indefinatly.
Anyway, I think I read somewhere they addressed that no-load instability issue by adding a note to their instructions.
Patient: "Doc, my leg hurts when I do this"
Doc: "Don't do that"
As far as what the reviewers say, it's amazing what you can feed people, and it's even more amazing what they'll eat just to be polite.
I remember not long ago on the class.org site.. his reviews I appreciated. Amps that got hyped up like non other by magazines got "sounds nice, but nothing special compared to the average class d you built yourself" or something to that effect.
Actually if they had a good circuit design they wouldnt' have those problems, best parts in the world can't withstand abuse indefinatly.
Anyway, I think I read somewhere they addressed that no-load instability issue by adding a note to their instructions.
Patient: "Doc, my leg hurts when I do this"
Doc: "Don't do that"
As far as what the reviewers say, it's amazing what you can feed people, and it's even more amazing what they'll eat just to be polite.
I remember not long ago on the class.org site.. his reviews I appreciated. Amps that got hyped up like non other by magazines got "sounds nice, but nothing special compared to the average class d you built yourself" or something to that effect.
What kind of output stage?
Hurtig said:NuForce is also known for their unstability. I have seen a handfull of NuForce amps after a total burn out. Not caused by heavy load... Simply caused by no load.
I heard about a fail rate of around 5-10%...![]()
Very impressing and really worth a patent.![]()
And once again from 6moons audio:
No further comment is needed when you read this.
There are 3 known cases of "bad" preamps that suffered high DC offset (in one case, the preamp manufacturer acknowledged this to the customer) and this DC killed our NuForce amp.
Lately, we discovered twin incidents where if the source device connected to the amp was turned off, the amp overheated and failed. This is rare but we have since added a cautionary note in the instruction manual.
We didn't realize the no-load overheating condition until we launched.
No further comment is needed when you read this.
PSU pumping? output filter resonance? shoot-through?
Yves Smolders said:And once again from 6moons audio:
No further comment is needed when you read this.
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