Recently I built a Hypex stereo amplifier and was really thrilled with the results and thought it was the best amplifier I had ever heard, posted here: http://www.diyaudio.com/forums/showthread.php?s=&threadid=133639&highlight=.
In the discussions It was mentioned that the Class-D Designs NX200 amplifier was a match for the Hypex and in fact perhaps even better. http://www.classd.ltd.uk/product.php?productid=16269 This intrigued me as I thought it was nearly impossible to improve on the Hypex and wondered if other people had found the same http://www.diyaudio.com/forums/showthread.php?s=&threadid=134498&highlight= but didn't get any satisfactory results as no one has seemed to have listened to one.
As they are so inexpensive compared with Hypex I decided to take the bull by the horns and try them out for myself. I bought the NX200s (which incidentally are not Class-D but Class AB amplifiers so would satisfy the purists) connected them up using the Hypex switch mode power supply and set back to listen to really superb sound.
All the clarity, dynamics and more was there compared to the Hypex and to my ears I thought the presence and soundstage was a little better.
All that I said about the Hypex in my review above can be applied to these NX200s so I'm not going to repeat myself here.
When you consider the price of the NX200s compared with the Hypex amplifiers, to my mind, the NX200s win hands down.
These amplifiers are crying out for someone to organise a Group Buy and depending on the quantities one could get them for as little as £26 each compared with £120 each for the Hypex. It's a no-brainer.
Incidentally, before someone starts jumping up and down I have no connection with any company and these views are my own personal ones.
In the discussions It was mentioned that the Class-D Designs NX200 amplifier was a match for the Hypex and in fact perhaps even better. http://www.classd.ltd.uk/product.php?productid=16269 This intrigued me as I thought it was nearly impossible to improve on the Hypex and wondered if other people had found the same http://www.diyaudio.com/forums/showthread.php?s=&threadid=134498&highlight= but didn't get any satisfactory results as no one has seemed to have listened to one.
As they are so inexpensive compared with Hypex I decided to take the bull by the horns and try them out for myself. I bought the NX200s (which incidentally are not Class-D but Class AB amplifiers so would satisfy the purists) connected them up using the Hypex switch mode power supply and set back to listen to really superb sound.
All the clarity, dynamics and more was there compared to the Hypex and to my ears I thought the presence and soundstage was a little better.
All that I said about the Hypex in my review above can be applied to these NX200s so I'm not going to repeat myself here.
When you consider the price of the NX200s compared with the Hypex amplifiers, to my mind, the NX200s win hands down.
These amplifiers are crying out for someone to organise a Group Buy and depending on the quantities one could get them for as little as £26 each compared with £120 each for the Hypex. It's a no-brainer.
Incidentally, before someone starts jumping up and down I have no connection with any company and these views are my own personal ones.
mitch90 said:
Well, to my mind that seems quite a nit-picking comment. Must have a Hypex devotee here. Please, let's have unbiased comments. We are talking about well over $100 each amplifier cheaper than the Hypex. That buys a hell of a lot of heatsink if indeed extra heatsinks are required. The efficiency of these amplifiers is supposedly similar to Hypex.
Hello cirrus18.
I am not a Hypex devotee, but I do think that
class-d topolgy is way to go, and that is my personal
opinion.
-"The efficiency of these amplifiers is supposedly similar to Hypex."-
Well from my experince with clas AB amps I find this hard
to belive, do you have any source to confirm this finding?
Price difference also can be attributed to the fact
that NX200 modules do not include overcurrent or overvoltage protection circuitry onboard.
What I am trying to say here is: fair comparison
between NX200 and UCD is something that can not be done very easy it is like comparing
apples to oranges.
Regards,
MITCH.
I am not a Hypex devotee, but I do think that
class-d topolgy is way to go, and that is my personal
opinion.
-"The efficiency of these amplifiers is supposedly similar to Hypex."-
Well from my experince with clas AB amps I find this hard
to belive, do you have any source to confirm this finding?
Price difference also can be attributed to the fact
that NX200 modules do not include overcurrent or overvoltage protection circuitry onboard.
What I am trying to say here is: fair comparison
between NX200 and UCD is something that can not be done very easy it is like comparing
apples to oranges.
Regards,
MITCH.
Ouroboros said:
Well, it's quite simple really. Because of the rather misleading name of this company "Class-D Designs" and to the fact that they look very similar to class-d amplifiers there was some confusion at the beginning to what they really were. They got included on this class-d forum. Because of the continuing interests here I've just continued it.
Anyway, as I am comparing it with the Hypex amplifiers, which are definitely class-d designs and do belong here, it's a moot point in which forum the posting should be in.
"The efficiency of these amplifiers is supposedly similar to Hypex."
If class AB, that's highly doubtful.
Watch out for specmanship games here. At full power out, they might approach comparable efficiency, but at less than full output power (where the class AB drops most of the supply voltage across its output transistors at the total current it has to feed to the load), a decent class D design can still have efficiency near its full power efficiency. Class AB efficiency tends to be quite poor in that situation. And when playing music, much less than full power is the normal situation, since absolute full power (i.e., just at clipping) should not be hit if you want things to sound good. That's why you can run things like Hypex or ICEpower with no, or almost no, heatsink, when it is used as a hifi amp. Don't try that with a class AB!
If class AB, that's highly doubtful.
Watch out for specmanship games here. At full power out, they might approach comparable efficiency, but at less than full output power (where the class AB drops most of the supply voltage across its output transistors at the total current it has to feed to the load), a decent class D design can still have efficiency near its full power efficiency. Class AB efficiency tends to be quite poor in that situation. And when playing music, much less than full power is the normal situation, since absolute full power (i.e., just at clipping) should not be hit if you want things to sound good. That's why you can run things like Hypex or ICEpower with no, or almost no, heatsink, when it is used as a hifi amp. Don't try that with a class AB!
Surely the real point is the sonics of the amp - this is what we are here for, I presume - slightly better than the tweaked out 180HG with HXR is a pretty good result, in my book.
I doubt that the efficiency is anything like the Hypex amps but you say they run cool at normal listening levels - what size heatsink have you mounted the modules on?
I doubt that the efficiency is anything like the Hypex amps but you say they run cool at normal listening levels - what size heatsink have you mounted the modules on?
I have them (Hypex) mounted on the side of the sheet metal chassis (180HG) and no other heatsinks. Barely warm to the touch.
Sonics (a subjective matter, of course) are to me better than any Class AB amps I've run. My previous amp was a decked-out, cascoded, servoed, coupling-capless MOSFET AB amp. Subjective evaluation is also influenced by psychology -- whether a listener is more positively effected by being around heatsinks, by glowing tubes, or by amps that physically seem not to be there. Probably the last suits me better than glowing things and big metal, but nothing wrong with the others.
Sonics (a subjective matter, of course) are to me better than any Class AB amps I've run. My previous amp was a decked-out, cascoded, servoed, coupling-capless MOSFET AB amp. Subjective evaluation is also influenced by psychology -- whether a listener is more positively effected by being around heatsinks, by glowing tubes, or by amps that physically seem not to be there. Probably the last suits me better than glowing things and big metal, but nothing wrong with the others.
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Joined 2003
Hi Cirrus18,
It looks as though you have posted this same information several months ago here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=134498
As it was shown in that thread, the Class-D company has poor business ethics, and better amplifier modules with accurate power rating can be purchased directly from the man that designed them, here. They are more expensive, but cost does reflect on quality in this case.
It has also been shown in This thread that the Class-D company has been very flaky to deal with, and some solder joints on their modules on the output transistors does not meet IPC specifications. If they are to offer free boards to people as a promotion for the company, these free boards should be the best performing boards of a production run, but they are sub-par at best.
I would not recommend an amp from the Class-D company to anyone.
It looks as though you have posted this same information several months ago here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=134498
As it was shown in that thread, the Class-D company has poor business ethics, and better amplifier modules with accurate power rating can be purchased directly from the man that designed them, here. They are more expensive, but cost does reflect on quality in this case.
It has also been shown in This thread that the Class-D company has been very flaky to deal with, and some solder joints on their modules on the output transistors does not meet IPC specifications. If they are to offer free boards to people as a promotion for the company, these free boards should be the best performing boards of a production run, but they are sub-par at best.
I would not recommend an amp from the Class-D company to anyone.
I agree cirrus, the proof of the pudding is in the eating & so far you are the only one to sample this particular pie & offer an opinion on how it tastes.
Dcibel reflects the attitude of a lot of people here with all sorts of negative statements about these modules without ever having heard one - indeed I'm sure he'll defend this stance but the bias in this approach is evident!
Dcibel reflects the attitude of a lot of people here with all sorts of negative statements about these modules without ever having heard one - indeed I'm sure he'll defend this stance but the bias in this approach is evident!
Member
Joined 2003
Member
Joined 2003
I agree that the company hasn't done themselves any favours with their free module offer which they seem not to have sent to all winners.
I would dispute your negative view of the construction quality of their boards - this is an opinion not a "fact"
But I again go back to sound & price - that's why cirrus report is useful & more reports on the modules would be useful.
I don't believe any winners who have received their modules have yet posted listening impressions.
I would dispute your negative view of the construction quality of their boards - this is an opinion not a "fact"
But I again go back to sound & price - that's why cirrus report is useful & more reports on the modules would be useful.
I don't believe any winners who have received their modules have yet posted listening impressions.
cirrus18,
Thanks for the review. I too have a pair of Hypex180HG and like the sound very much. I wanted to try the NX200 but with all the bad comments in this forum (none regarding how it sounds), I have not purchased them. Elsewhere, I read that changing the caps to ELNA Silmic or Cerafine will improve the sound (not in thethe NX, but in something similar)
Thanks for the review. I too have a pair of Hypex180HG and like the sound very much. I wanted to try the NX200 but with all the bad comments in this forum (none regarding how it sounds), I have not purchased them. Elsewhere, I read that changing the caps to ELNA Silmic or Cerafine will improve the sound (not in thethe NX, but in something similar)
How's this for an idea.
I may find out that I'm made redundant tomorrow and if I am, I'll buy a couple of NX200 modules and build an amp. I've got a 330VA transformer that will do the job, and a bunch of DNM slit foil caps needing a home. Got a few unpopulated power supply boards and a couple of rectifiers so all I need is a case, some connectors and time (which I'll have plenty of).
I've already got a UCD180HG power amp (not with HPR/HNR regs) so I can do a comparison.
I've been thinking about buying a couple for a while, as I was intrigued by the amount of bitching that there had been over something that hardly anyone had tried.
I've no agenda - I'd be happy if the scandelous upstart proved victorious over the current flavour of the month. Likewise, I'd be content if my (more expensive) existing amp reigned supreme.
C'mon guys. No-one goes mad over bad manufacturer PR or questinable build quality when someone's found an amazingly cheap chinese tube amp (I'm not saying all chinese kit is badly built - a lot of it is great). Let's extend class-d design the same courtesy: ignore the poor customer service, ignore the fact that some have questioned build quality and let's start seeing what we can do with these cheap amp modules.
That is what makes this forum great
I may find out that I'm made redundant tomorrow and if I am, I'll buy a couple of NX200 modules and build an amp. I've got a 330VA transformer that will do the job, and a bunch of DNM slit foil caps needing a home. Got a few unpopulated power supply boards and a couple of rectifiers so all I need is a case, some connectors and time (which I'll have plenty of).
I've already got a UCD180HG power amp (not with HPR/HNR regs) so I can do a comparison.
I've been thinking about buying a couple for a while, as I was intrigued by the amount of bitching that there had been over something that hardly anyone had tried.
I've no agenda - I'd be happy if the scandelous upstart proved victorious over the current flavour of the month. Likewise, I'd be content if my (more expensive) existing amp reigned supreme.
C'mon guys. No-one goes mad over bad manufacturer PR or questinable build quality when someone's found an amazingly cheap chinese tube amp (I'm not saying all chinese kit is badly built - a lot of it is great). Let's extend class-d design the same courtesy: ignore the poor customer service, ignore the fact that some have questioned build quality and let's start seeing what we can do with these cheap amp modules.
That is what makes this forum great
Sharpie31, I hope you stay too employed to spend too much time building amplifiers. Being without a paycheck is no fun (at least not for long!).
Everyone should probably back off on cirrus18, why can't he give his opinion like anyone else, and he is the only one who has heard the amps anyway. Maybe ClassD (company) puts something in the boards that the German guy doesn't?
But it does seem that that discussion is more suited to the "Solid State" forum rather than the "ClassD", seeing as the only thing that is ClassD about those amps is the name of the company that makes them!
One question, though, cirrus18 -- where in the world are you getting heatsinks for "peanuts"?? In my experience, cost of decent heatsinks that look good in a build are third in line behind (#1) enclosure and (#2) power supply, at least when building an amp from scratch (though that experience was mostly with Class A building). Notice that power devices and low level circuitry run 4th in cost in that rundown... transistors and resistors are relatively CHEAP at least from electronic distributor catalogs. Is there a cheap surplus heatsink company that I'm not getting ads from?
Everyone should probably back off on cirrus18, why can't he give his opinion like anyone else, and he is the only one who has heard the amps anyway. Maybe ClassD (company) puts something in the boards that the German guy doesn't?
But it does seem that that discussion is more suited to the "Solid State" forum rather than the "ClassD", seeing as the only thing that is ClassD about those amps is the name of the company that makes them!
One question, though, cirrus18 -- where in the world are you getting heatsinks for "peanuts"?? In my experience, cost of decent heatsinks that look good in a build are third in line behind (#1) enclosure and (#2) power supply, at least when building an amp from scratch (though that experience was mostly with Class A building). Notice that power devices and low level circuitry run 4th in cost in that rundown... transistors and resistors are relatively CHEAP at least from electronic distributor catalogs. Is there a cheap surplus heatsink company that I'm not getting ads from?
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