VTV Hypex NC1200 Tear Down and Recommendation

[C. Cook]

You are missing the point. you running your amp at very low levels is irrelevant. the amp is sold as delivering 700 with into 4 ohms. it will be in meltdown at that level.

Now turn the amp over and measure the base temperature and the box internal air temp.

What other manufacturers do is irrelevant. You need to stop making apologies for this deficient design.

But you're mixing up whose design is deficient. In the case (pun not intended) of heat sinking it would be Ghent, not VTV. And tons of other OEM Hypex products use Ghent cases with no additional heat sinking. IF it was a huge problem, don't you think we'd have heard something by now?

Now I'm not saying Ghent's case is the ideal one to use for this application and I'm also not disputing that your amp was a shitshow and I'm glad you were able to recoup your money. But again, it is completely relevant if we're limiting our discussion of the design to the heat sinking characteristics for me to want to see any other OEM mfg. that's actually using the fin-type HS you showed. I don't think anyone is, hence everyone else's design is also deficient according to that logic. That said, I repeat there were OTHER glaring issues with the one you got, so I want to keep this specific to heat.

The measurements I took were at the bottom of the amp, no need to turn it over. I also used the feel test. Never got hot enough to make me want to take my hand away and running much cooler than the last good A/B amp I had, as expected.

Nobody realistically expects to ever tap into the 700th watt or even close, at least not in any continuous fashion. Like it or not, the heat issues I was experiencing on day one are gone now and I am not sure why, but I have no vested interest in the success of VTV and therefore no reason to lie or intentionally misunderstand what's happening. At some point I *MAY* get in there and fix up a few of the minor soldering issues and lack of shrink wrap on some of the inside terminal wiring.

 

[mrmojo2022]

But you're mixing up whose design is deficient. In the case (pun not intended) of heat sinking it would be Ghent, not VTV. And tons of other OEM Hypex products use Ghent cases with no additional heat sinking. IF it was a huge problem, don't you think we'd have heard something by now?

Now I'm not saying Ghent's case is the ideal one to use for this application and I'm also not disputing that your amp was a shitshow and I'm glad you were able to recoup your money. But again, it is completely relevant if we're limiting our discussion of the design to the heat sinking characteristics for me to want to see any other OEM mfg. that's actually using the fin-type HS you showed. I don't think anyone is, hence everyone else's design is also deficient according to that logic. That said, I repeat there were OTHER glaring issues with the one you got, so I want to keep this specific to heat.

The measurements I took were at the bottom of the amp, no need to turn it over. I also used the feel test. Never got hot enough to make me want to take my hand away and running much cooler than the last good A/B amp I had, as expected.

Nobody realistically expects to ever tap into the 700th watt or even close, at least not in any continuous fashion. Like it or not, the heat issues I was experiencing on day one are gone now and I am not sure why, but I have no vested interest in the success of VTV and therefore no reason to lie or intentionally misunderstand what's happening. At some point I *MAY* get in there and fix up a few of the minor soldering issues and lack of shrink wrap on some of the inside terminal wiring.

How is this Ghents fault?

They just manufacture cases. it's up to VTV how they get used. VTV should have realised this case has totally inadequate cooling. even if they missed it during design, which us inexcusable, they should noticed it burning their hands when on test. I doubt they even performed a full range of tests. Screw the bits in a cheap case and job done.

People may well use the amp to its capabilities of 700 watts. It is sold as being capable of doing so. low impedance and insensitive speakers are it's fundamental market.

Of course it's a problem. YOU explicitly mentioned it and using fans to keep it acceptably cool, and you are not driving it hard.

Please stop trying to excuse the inexcusable. I just don't know how you can recommend an amateur built amp that overheats. the design is not fit for purpose.

 

[C. Cook]

They just manufacture cases. it's up to VTV how they get used. VTV should have realised this case has totally inadequate cooling.

Of course it's a problem. YOU explicitly mentioned it and using fans to keep it acceptably cool, ad you are not driving it hard.

Please stop trying to excuse the inexcusable. I just don't know how you can recommend an amateur built amp that overheats.

Should everyone else using Ghent cases (including for nc400/500 projects) realize that the case has inadequate cooling characteristics? There are a lot of them! So if Ghent won't provide heat sinking data, and numerous OEM-based sellers are using them for various Hypex implementations due to lack of other quality options, then yes the faulty design is Ghent's as he's the one marketing his case for use with the aforementioned amplifier modules and SMPSs. If VTV was a big company with lots of test and eval capabilities, perhaps they could have confirmed that the Ghent cases are adequate for heat, but this unit heated up REALLY hot for a few days up until I made the OP and then started behaving 'normally'...it's no longer 'overheating' and is performing within a reasonable and expected range.

For the third time, I'm NOT USING FANS. LOL

There's nothing inexcusable in the particular amp that VTV sent me. There are some less than perfect areas, and it DOESN'T OVERHEAT (anymore).

I'm playing very loud music now for going on 2.5 hours. Will I ever be sending 700W into ANY speaker? HIGHLY unlikely and I like my music loud. And again, if you can't find any other OEM manufacturers that are managing the heat sinking on the Hypex ncXXXy modules properly (or differently) then I think it's safe to assume that a whole lot of Hypex based amps are going to be melting down from inadequate heat dissipation in the next few years given that the VTV/Ghent build is no different than anyone else's from the perspective of heat. Well, that or the fact that the Ghent case is as adequate as anyone else's.

Just to be thorough, I'll be switching in some less efficient speakers for a test in the next few weeks/months as work allows. Will be interesting to compare the temperatures.

The recommendation, which I stand by IF the build quality is at least as good as the one I got (assuming they've gotten better at QC since yours was sent), takes into account numerous factors including price, form factor, performance and others. For the price to performance ratio of the one I got, it's pretty high up there and since I have nothing to hide, I'll be the first one to post any followups if the thing fails within the next 2 years as I plan to keep and enjoy it until it does.

 

[C. Cook]

I don't know what happened to your most recent reply, but you asked how is this Ghent's fault.

Assuming that his cases ARE in fact inadequate for heat (an assumption you've made but I haven't seen backed up in numbers yet) this is how: https://www.ghentaudio.com/kit/nc1200.html

Now, IF - and it's a big if for me especially since mine is NOT overheating - but if Ghent provides data on the heat dissipation properties of his cases (which I think we both agree he doesn't - never replied to my email asking) then VTV could do the necessary calculations and testing to ensure that the heat sinking is adequate for the NC1200 build using the case that Ghent is marketing for that application. Ghent is also one of the biggest suppliers of the OEM/DIY cases, so again I'd expect to have seen someone here or elsewhere complaining that their Hypex amp melted down or overheats. I think I'm going to ask Hypex's opinion on whether the case is adequate for the NC1200s and SMPS3k700 as far as heat goes.

 

[boXem]

They just manufacture cases. it's up to VTV how they get used. VTV should have realised this case has totally inadequate cooling.

Of course it's a problem. YOU explicitly mentioned it and using fans to keep it acceptably cool, ad you are not driving it hard.

Please stop trying to excuse the inexcusable. I just don't know how you can recommend an amateur built amp that overheats.

Should everyone else using Ghent cases (including for nc400/500 projects) realize that the case has inadequate cooling characteristics? There are a lot of them! So if Ghent won't provide heat sinking data, and numerous OEM-based sellers are using them for various Hypex implementations due to lack of other quality options, then yes the faulty design is Ghent's as he's the one marketing his case for use with the aforementioned amplifier modules and SMPSs. If VTV was a big company with lots of test and eval capabilities, perhaps they could have confirmed that the Ghent cases are adequate for heat, but this unit heated up REALLY hot for a few days up until I made the OP and then started behaving 'normally'...it's no longer 'overheating' and is performing within a reasonable and expected range.

For the third time, I'm NOT USING FANS. LOL

There's nothing inexcusable in the particular amp that VTV sent me. There are some less than perfect areas, and it DOESN'T OVERHEAT (anymore).

I'm playing very loud music now for going on 2.5 hours. Will I ever be sending 700W into ANY speaker? HIGHLY unlikely and I like my music loud. And again, if you can't find any other OEM manufacturers that are managing the heat sinking on the Hypex ncXXXy modules properly (or differently) then I think it's safe to assume that a whole lot of Hypex based amps are going to be melting down from inadequate heat dissipation in the next few years given that the VTV/Ghent build is no different than anyone else's from the perspective of heat. Well, that or the fact that the Ghent case is as adequate as anyone else's.

Just to be thorough, I'll be switching in some less efficient speakers for a test in the next few weeks/months as work allows. Will be interesting to compare the temperatures.

The recommendation, which I stand by IF the build quality is at least as good as the one I got (assuming they've gotten better at QC since yours was sent), takes into account numerous factors including price, form factor, performance and others. For the price to performance ratio of the one I got, it's pretty high up there and since I have nothing to hide, I'll be the first one to post any followups if the thing fails within the next 2 years as I plan to keep and enjoy it until it does.

Could you please name these tons of other manufacturers using Gent cases for Hypex builds? Just curious.
At boXem we do not offer stereo NC500 because of thermal management. Our case (own design BTW) is able to handle one mono NC1200 and it took us some effort to go there. So yes, there are some small manufacturers taking care of thermal design and not just slapping modules in a diy box.

 

[C. Cook]

Could you please name these tons of other manufacturers using Gent cases for Hypex builds? Just curious.
At boXem we do not offer stereo NC500 because of thermal management. Our case (own design BTW) is able to handle one mono NC1200 and it took us some effort to go there. So yes, there are some small manufacturers taking care of thermal design and not just slapping modules in a diy box.

That's actually not an easy question to answer as it's hard to find exact information on how many (commercial) manufacturers are using Ghent's cases. I may have been a little hyperbolic there lol. Probably not "tons" of for-profit builders using them. However, there are likely "tons" of individual DIY-ers and smaller, less well known Hypex OEM complete amp providers using them. I know of two guys who are no longer in the business (for unrelated reasons) that both had Hypex OEM accounts and built and sold amps on eBay and they both used Ghent's cases exclusively, well, at least in the types of products I discussed with them.

But man, I've seen dozens of stereo NC500 and NC400 builds in Ghent cases, so I hope their amps don't fail due to heat (again, assuming that they don't have adequate heat sinking ability). Yeah, for the most part it's just slapping modules into a box, but one would like to think that at some point in the past Ghent provided data on heat dissipation characteristics - or - someone actually set about measuring themselves.

To the underlying point, however, have you ever looked inside a Nord or Apollon Hypex-based amp? To my knowledge neither of them use any special heat sinking above and beyond bolting the modules to the bottom of the case! I tore down my own Nord Purifi amp and confirmed this. Of course, their cases MIGHT have better heat dissipation than Ghent's due to the size and thickness of the aluminum they use but I don't know this for a fact. I also unscrewed one of the Purifi modules and the SMPS from the Nord case the other night and there's no paste in there either. So what I'm saying is that if in fact these other people aren't properly sinking the heat in their products, we're going to see a lot of failures and I haven't found many instances of that in my (admittedly limited) searching for it online, including at ASR and DIY forums. Another way of putting it is that Ghent/VTV aren't doing anything fundamentally different in this regard than scores of other DIYers and commercial resellers are.

That said, I'd be interested in learning more about your experience with coming to the correct design for heat with the NC1200 and whether you have data (something that isn't easily forthcoming out of Ghent, I've learned) on the various attempts at getting there. I'm also interested to know if you think any other OEM reseller is handling heat dissipation properly for these Hypex products and if so who are they? I haven't looked you up yet, but do you guys sell cases alone or just complete amps? I'm always looking for different options when I get around to a new DIY project.

Oh yeah, I forgot to ask: In your mono nc1200 amps, what are the maximum temps (internal air, case surface, whatever) you're getting now that you've arrived at the correct design for your product?

 

[mrmojo2022]

I don't know what happened to your most recent reply, but you asked how is this Ghent's fault.

Assuming that his cases ARE in fact inadequate for heat (an assumption you've made but I haven't seen backed up in numbers yet) this is how: https://www.ghentaudio.com/kit/nc1200.html

Now, IF - and it's a big if for me especially since mine is NOT overheating - but if Ghent provides data on the heat dissipation properties of his cases (which I think we both agree he doesn't - never replied to my email asking) then VTV could do the necessary calculations and testing to ensure that the heat sinking is adequate for the NC1200 build using the case that Ghent is marketing for that application. Ghent is also one of the biggest suppliers of the OEM/DIY cases, so again I'd expect to have seen someone here or elsewhere complaining that their Hypex amp melted down or overheats. I think I'm going to ask Hypex's opinion on whether the case is adequate for the NC1200s and SMPS3k700 as far as heat goes.

Your data and statements tells us the case has inadequate cooling

This amp tends to heat up A LOT on the bottom in the back on each side,. I did purchase a set of 4 box fans to place underneath and wired up a little control knob to keep it cool because the temps were getting up to about 130-150F. That's a lot hotter than NC500s run in my experience.

whatever Ghent market it is explicitly VTVs responsibility to design a product that has adequate cooling. It obviously will overheat if used through the modules designed operating range.

It's late, I'm going to bed, can't be bothered to argue with you any further.

 

[mrmojo2022]

Could you please name these tons of other manufacturers using Gent cases for Hypex builds? Just curious.
At boXem we do not offer stereo NC500 because of thermal management. Our case (own design BTW) is able to handle one mono NC1200 and it took us some effort to go there. So yes, there are some small manufacturers taking care of thermal design and not just slapping modules in a diy box.

Good point, who else is using Ghent cases? really glad to see you are thinking about this design aspect.

 

[C. Cook]

Your data and statements tells us the case has inadequate cooling

This amp tends to heat up A LOT on the bottom in the back on each side,. I did purchase a set of 4 box fans to place underneath and wired up a little control knob to keep it cool because the temps were getting up to about 130-150F. That's a lot hotter than NC500s run in my experience.

whatever Ghent market it is explicitly VTVs responsibility to design a product that has adequate cooling. It obviously doesn't will overheat if used through the modules designed operating range.

Dude, this is the last time I'm going to dignify more retrievals of the exact text of my ORIGINAL post which I've already addressed too many times to count lol. The data from tonight, which I provided in pictures, says that the amp is performing to spec and well under heat limitations. Also again, for the FOURTH time now, I bought the fans based on my initial measurements, but...sigh...(begins to tire mentally) am not using them anymore for two reasons: 1) They're not necessary now! and 2) I want to make this amp fail within the two year warranty if in fact the heat dissipation isn't adequate (something I've also said like 6 times now).

For everyone else's benefit: THE AMP NOW SEEMS TO BE PERFORMING JUST FINE WITH HEAT AND I'M NOT USING ANY FANS AT ALL. It's still a mystery to me why it got so hot that one day I measured and made the OP.

I'm not sure what you're not understanding w/r/t Ghent and what he's marketing. The product page I linked to is a case specifically drilled (and designed one would hope? unlikely) for the stereo nc1200 implementation that VTV is providing. Ghent is claiming that his case is adequate for this configuration. Is it ALSO on the person/company who's actually selling the amps in Ghent's cases to confirm that they in fact do perform adequately? Sure, and VTV may not have been able to do this. But it doesn't matter anymore because the amp is running perfectly 'cool' at high volumes with a maximum temp of 112F where previously it got up around 135 and felt as though it could have gotten hotter.

I'll get back to this thread when I have had the chance to swap in some less efficient, lower impedance speakers and take temp measurements.

 

[C. Cook]

It would appear that I'm not alone in initially turning to exterior fans to cool a Hypex based amp.

Ghent Audio 3 x NC400 case - cooling

Just a quick question: Has anyone used Ghent Audio's case for 3 modules and know whether, with 3 x SMPS 600 in there, is the cooling sufficient? Here is the link to the case: ghentaudio --- NCORE-3CH Hypex & NCore NC400 3CH DIY Case-kit P.S. Is there an SMPS that can safely run 3 x NC400s? I...

www.diyaudio.com

Not that this is any proof of anything or a statement of confidence in any one particular product like my VTV or Ghent's cases, but yeah, let me amend my statement to say that if I do ever decide to use this thing to run a disco or rock concert, I'll probably break out the fans just to be safe lmao...

 

[mrmojo2022]

Well the Hypex data shows that this amp won't run cool in that case and the calculations tie up well with your initial measurements. A manufacturer @boXem | audio also has found a case of similar properties to be inadequate for cooling stereo nc1200.

If you are going to do further tests as you mentioned, then you need to do them properly. measure the base of the amp enclosure, not the side, and the internal air temp. you need to do this whilst running a known power output onto a dummy load.

 

[C. Cook]

Well the Hypex data shows that this amp won't run cool in that case and the calculations tie up well with your initial measurements. A manufacturer @boXem | audio also has found a case of similar properties to be inadequate for cooling stereo nc1200.

If you are going to do further tests as you mentioned, then you need to do them properly. measure the base of the amp enclosure, not the side, and the internal air temp. you need to do this whilst running a known power output onto a dummy load.

Does the Hypex data on the nc1200 say that though? I have been measuring the underside of the case. It will be difficult to get any kind of thermometer or thermocoupling into the inside to measure air temps, but I'll see about pointing the IR thermometer down into one of the tiny holes.

I asked boXem for some data from their temperature testing and he hasn't responded yet. I wasn't aware they actually performed tests on the Ghent cases.

 

[C. Cook]

So where is boXem's heat data? Where is the proof that anyone else is heatsinking better?

Sorry just me or is this a little suspicious given the previous engagement?

 

[boXem]

So where is boXem's heat data? Where is the proof that anyone else is heatsinking better?

Sorry just me or is this a little suspicious given the previous engagement?

I was ready to give some data, but in front of such a behavior, well...

 

[mrmojo2022]

Look, I get you are invested in your new amp and don't want your "recomendation" contradicted, but the data and evidence speaks for itself.

I have seen plenty of threads here showing VTVs lack of technical competence understanding of electrical safety and poor quality. On the other hand @boXem | audio products appear well designed and built. no we do not have any association, just a shared view based on technical data and analysis. you really shouldn't cast aspersions on @boXem | audio when this is clearly a subject you don't have the knowledge to comment upon.

Why do you keep trying to create diversions by talking about other manufacturers "doing it better?" the thread is entirely about this specific VTV product.

Why don't you do a bit of research so you can understand the data Hypex have provided on thermal management and heatsinking. this would be far better than blindly arguing and defending the VTV design. BTW you will get better temp measurements if you place a square of matt black electrical tape on the case. this will help match emissivity. The ir temp gun won't measure through the holes, but it will be hotter, by probably 10 to 15 deg C, inside.

 

[mrmojo2022]

But it doesn't matter anymore because the amp is running perfectly 'cool' at high volumes with a maximum temp of 112F where previously it got up around 135 and felt as though it could have gotten hotter.

I'll get back to this thread when I have had the chance to swap in some less efficient, lower impedance speakers and take temp measurements.

Maybe the drop in temperature from what you measured in the OP (150 deg F 65 deg C) is because you took the lid off the case? I have just noticed this in the pictures you posted.

How about posting a youTube video of the amp running for an hour at idle no music then turn it over and measure the temp of the bottom side of the case.

 

[mrmojo2022]

Does the Hypex data on the nc1200 say that though?

The nc1200 isn't fundamentally any more efficient than the nc500. from the datsheets both the Nc500 and the nc1200 efficiency at full power = 93% in fact the nc1200 has significantly higher idle losses. Sat doing nothing the nc500 uses 6 watts whilst the nc1200 uses 15 watts.

The smps3k also has idle losses of 15 watts. so let's calculate what temp the case will get to at idle not playing music.

2x nc1200 = 30watts
Smps3k = 20 watts heat dissipation (at 30 watts load from graph in datasheet.)
Total = 50 watts

Earlier calculation estimated your case to have a thermal resistance of 1.1 deg C / watt. So it will run at about 55 deg C or 131 deg F at idle. this is quite consistent with expectations based my own experience of the single nc1200 amp.
Remarkable how in your OP you said the temp was 130 to 150 deg F. Exactly what I would expect based on idle/light load


This amp tends to heat up A LOT on the bottom in the back on each side, so it would appear that it's the n-core modules that are responsible and not the big 3-channel-capable SMPS. In the past using NC500s it's been the SMPS that generates the most heat and it the larger XFMR seems to be the primary source, pun intended. I did purchase a set of 4 box fans to place underneath and wired up a little control knob to keep it cool because the temps were getting up to about 130-150F. That's a lot hotter than NC500s run in my experience. The fans aren't audible since I've got the amp in an enclosed built-in cabinet under the TV, which also contributes to heat build up over time.

 

[Gorgonzola]

Slagging VTV is a bit of a sport at ASR. That's not to say the VTV is high-end on construction quality but by-and-large the stuff is sound.

I've owned VTV's NC252MP stereo and presently own their Purifi 1ET400A stereo with VTV buffers and have no problems whatever. Warren Coleman has given me great, personalized service on account of a problem that was entirely my own making, (having to do with swapping out Hypex buffers for the VTV).

Everything looks fine to me: see my pic attached. Shown with VTV buffers.

 

[C. Cook]

Maybe the drop in temperature from what you measured in the OP (150 deg F 65 deg C) is because you took the lid off the case? I have just noticed this in the pictures you posted.

How about posting a youTube video of the amp running for an hour at idle no music then turn it over and measure the temp of the bottom side of the case.

LOL and what exactly is it that you think this picture is Showing? I haven't taken measurements with the top off, so I'm curious as to whether you are under the mistaken impression that the picture above shows a part of the case rather than the sound bar of my LG OLED TV.

Sure I have no problem at all posting a YouTube video once I've gotten some of my actual work done; it's suffered slightly due to this ongoing nag fest.

 

[C. Cook]

The nc1200 isn't fundamentally any more efficient than the nc500. from the datsheets both the Nc500 and the nc1200 efficiency at full power = 93% in fact the nc1200 has significantly higher idle losses. Sat doing nothing the nc500 uses 6 watts whilst the nc1200 uses 15 watts.

The smps3k also has idle losses of 15 watts. so let's calculate what temp the case will get to at idle not playing music.

2x nc1200 = 30watts
Smps3k = 20 watts heat dissipation (at 30 watts load from graph in datasheet.)
Total = 50 watts

Earlier calculation estimated your case to have a thermal resistance of 1.1 deg C / watt. So it will run at about 55 deg C or 131 deg F at idle. this is quite consistent with expectations based my own experience of the single nc1200 amp.
Remarkable how in your OP you said the temp was 130 to 150 deg F. Exactly what I would expect based on idle/light load


This amp tends to heat up A LOT on the bottom in the back on each side, so it would appear that it's the n-core modules that are responsible and not the big 3-channel-capable SMPS. In the past using NC500s it's been the SMPS that generates the most heat and it the larger XFMR seems to be the primary source, pun intended. I did purchase a set of 4 box fans to place underneath and wired up a little control knob to keep it cool because the temps were getting up to about 130-150F. That's a lot hotter than NC500s run in my experience. The fans aren't audible since I've got the amp in an enclosed built-in cabinet under the TV, which also contributes to heat build up over time.

It may not be "fundamentally more efficient" than the nc500s, but it also doesn't put out TWICE the heat along with twice the power. Also, the front of the case which is where the SMPS is has never even gotten to 100F. It was the back where the nc1200 modules are that initially "over" heated.