VTV Hypex NC1200 Tear Down and Recommendation

[mrmojo2022]

1. And you have nothing but speculation to offer on how any other case might differ from Ghent's case with regard to position, shape and airflow allowed. The March case appears to have even fewer vent holes than Ghent.

2. Of course it's about "fins" when they're used properly. Why do you think that the plate fin topology for heat sinks has been so widely used for so long? Clearly these "fins" would be best employed where the devices that generate heat (transistors usually) are attached on one side (the "plate") while the other side (the "fins") is exposed to outside air. I've never seen a Hypex OEM build with anything close to this and Hypex doesn't have any literature specifically referencing plate fin heatsinks that I've seen. However, I think we could agree that if someone came up with a way to bolt the ncxxxy modules to a plate fin heatsink, it would do a great deal to aid in heat dissipation above and beyond the majority of case designs currently on the market.

Far from it. I have provided informed commentary data and calculations to explain why you burnt your hands on your amp case.

I haven't seen reports of the March burning peoples hands and its running at less than 40 deg C in the above data, so as I said you need to take a look at the surface area of the plate to case contact and the air flow. Why don't you contact March?

Aren't you concerned that your amp got so hot, or why as you now claim, it suddenly doesn't? something is wrong either way.

Anyway, it's late here. I'm off.

 

[C. Cook]

Far from it. I have provided informed commentary data and calculations to explain why you burnt your hands on your amp case.

Aren't you concerned that it got so hot, or why as you now claim, it suddenly doesn't? something is wrong either way.

I never "burnt" my hands. Just because we're so far down this rabbit hole already, I figured I'll offer some personal context. Compared to my friends, one of whom is a cook/chef and the other works on high pressure/high temperature hydraulics, I have a very low tolerance to heat. I also take my showers MUCH cooler than any women I ever dated, including my wife and consider my food "super hot" when others simply think that's the right temp. It was uncomfortably hot the first time I decided to investigate, but the unit never reached higher than 135F - I only assumed it would get to 150; incorrectly thus far. Could still happen again and could possibly reach 150. I'll definitely share the readouts if it does, and I have just downloaded a FLIR app for my smartphone.

Yes, I am concerned which is why I'm still here arguing with you and trying to make some headway in comparing what Ghent's cases are like to others like March, Nord, Apollon and even boXem who all use their own custom cases with no significant additional airflow or heat sinking, and in some cases even less airflow based on photos. That's also why I took the time to do 'detailed' temperature readings and posted them here as well as saying I'm going to continue to monitor the situation and attempt to drive the amp as hard as I reasonably can in so doing. I have nothing to hide, and I'll reiterate that I'm as confused as you are about why it heated up so high at one point but hasn't even come within 20 degrees F of 135 in the time since. It's a mystery to me and I don't think the modules are performing according to the heat dissipation numbers provided. Not linearly anyway as the amp actually cools down slightly (5-7 degrees F) when playing louder music and runs much 5-7 degrees F hotter with lower volume music playing.

We disagree on who bears the majority of blame inasmuch as heat dissipation is concerned assuming all previous calculations are accurate. I'm telling you that Ghent is actively marketing his case for a stereo nc1200 amplifier and that VTV and presumably other OEM (definitely DIY) builders are buying and using them for this application. If Ghent's case is demonstrably incapable of dissipating the right amount of heat for a given application, he needs to stop advertising them that way and then OEM and DIYers can take action accordingly. This could potentially be a huge problem and it's not endemic or unique to VTV.

 

[C. Cook]

Let me also say that I've seen numerous users on various forums saying they are using cooling fans for a variety of Hypex and other class d amplifiers.

Admittedly, I wouldn't put this VTV inside a small enclosed rack and use it to power discotheque speakers for an all night party, but so far it's doing just fine with heat dissipation in my enclosed audio shelf playing at low to high volume with the type of music and movies I tend to listen to.

 

[mrmojo2022]

. Recall I said that it burned my hand to touch it before.

I never "burnt" my hands.

Can you get your story straight?

Or is this just another convenient hindsight revision?

 

[C. Cook]

Can you get your story straight?

Or is this just another convenient hindsight revision?

You should be a TV detective. I'd have already been convicted by now despite the lack of actual evidence lol. Or maybe you just like to argue. Probably the latter.

Yes I said it burned my hand, but I later qualified that with additional information. If anything all I'm guilty about is trying to have a free flowing conversation with someone who's acting like an Internet Sherlock Holmes and trying to play "gotcha" every chance he gets. Clearly if I'd actually BURNT my hand, medical attention would have been necessary, correct? I also don't like going back to edit for precise language, rather I prefer to let the context come out as the conversation continues. For that reason and the fact that it hasn't heated up that hot again I have no desire to go back and edit the OP to suit your liking or even to convince someone else to buy an nc1200 amp in a Ghent case who might have (perhaps rightfully) assumed that I literally burned my hand or that it was hot enough to actually burn flesh.

You're the one with a vested interest here; not me. Actions speak louder than words, and your continued hounding without admitting that other makes are also using insufficient (or insufficiently documented) heat sinking seems to be more important than coming to an accurate conclusion that could help lots of people contemplating purchasing Hypex OEM based amps. I personally couldn't care less if anyone buys VTV products or Ghent cases so I have no reason to make "convenient hindsight revisions" to anything I've said. You keep skipping around the fact that Ghent is the one advertising his case for the exact application that VTV is selling and that from every picture I've ever seen of Nord, Apollon, March Audio, and other DIY projects there is the same amount or less visible heat sinking as VTV/Ghent.

You don't like VTV. No, you HATE VTV, and that's your prerogative but it's blinding you to a larger issue. Anyone reading this thread objectively will see that I've never dismissed your experience or attempted to persuade anyone to buy any product. But you're on a witch hunt against one particular OEM provider while ignoring or being ignorant of the fact that far more people stand to lose money purchasing Ghent cases than would ever buy a VTV product. I mean seriously, what kind of volume do you think VTV is doing compared to Ghent? Think about all the heat failures that could result! Let me know if that doesn't make sense and I'll try to rephrase or make a "convenient hindsight revision" lol.

To anyone else reading, I'm interested in comparing heat dissipation characteristics of different cases with dual nc500 or nc1200 configurations to what I've posted about VTV/Ghent. Just installed a FLIR app and plan to take some pictures later which of course I will post here regardless of the outcome. Also if anyone can recommend a good FLIR app, I'd appreciate it bc none of the ones I found are rated higher than 3.9 stars in the Play Store. Dammit, I have to get a thermal camera first. Thought there might be an app that could do it by way of calculations. More on that later when I've found a suitable one that isn't too expensive.

 

[mrmojo2022]

You should be a TV detective. I'd have already been convicted by now despite the lack of actual evidence lol. Or maybe you just like to argue. Probably the latter.

Yes I said it burned my hand, but I later qualified that with additional information. If anything all I'm guilty about is trying to have a free flowing conversation with someone who's acting like an Internet Sherlock Holmes. Clearly if I'd actually BURNT my hand, medical attention would have been necessary, correct? I also don't like going back to edit for precise language, rather I prefer to let the context come out as the conversation continues. For that reason and the fact that it hasn't heated up that hot again I have no desire to go back and edit the OP to suit your liking or even to convince someone else to buy an nc1200 amp in a Ghent case who might have (perhaps rightfully) assumed that I literally burned my hand or that it was hot enough to actually burn flesh.

You're the one with a vested interest here; not me. Actions speak louder than words, and your continued hounding without admitting that other makes are also using insufficient (or insufficiently documented) heat sinking seems to be more important than coming to an accurate conclusion that could help lots of people contemplating purchasing Hypex OEM based amps. I personally couldn't care less if anyone buys VTV products or Ghent cases so I have no reason to make "convenient hindsight revisions" to anything I've said. You keep skipping around the fact that Ghent is the one advertising his case for the exact application that VTV is selling and that from every picture I've ever seen of Nord, Apollon, March Audio, and other DIY projects there is the same amount or less visible heat sinking as VTV/Ghent.

You don't like VTV. No, you HATE VTV, and that's your prerogative. Anyone reading this thread objectively will see that I've never dismissed your experience or attempted to persuade anyone to buy any product. But you're on a witch hunt against one particular OEM provider while ignoring or being ignorant of the fact that far more people stand to lose money purchasing Ghent cases than would ever buy a VTV product. I mean seriously, what kind of volume do you think VTV is doing compared to Ghent? Think about all the heat failures that could result! Let me know if that doesn't make sense and I'll try to rephrase or make a "convenient hindsight revision" lol.

To anyone else reading, I'm interested in comparing heat dissipation characteristics of different cases with dual nc500 or nc1200 configurations to what I've posted about VTV/Ghent.

It's gets way too, then it doesn't get too hot. it burns your hands then it doesn't burn your hands. The data indicates it will get hot. If it doesn't anymore then something significant has changed. yet despite this worrying behaviour you still recommend it.

This isn't a witch hunt, it's just what you have said is happening.

Goodnight.

 

[C. Cook]

It's gets way too, then it doesn't get too hot. it burns your hands then it doesn't burn your hands. The data indicates it will get hot. If it doesn't anymore then something significant has changed. yet despite this worrying behaviour you still recommend it.

This isn't a witch hunt, it's just what you have said is happening.

Goodnight.

Yep. It got way too hot for me, now it doesn't as the pictures of the temperature readings I posted clearly indicated. I don't know why any more than you do, but there's nothing logically inconsistent with device behavior changing over time or even anomalies happening. From my more recent measurements and observations, the Ghent case is doing a sufficient job, for now, of dissipating heat at the volumes I've tried. At the core of your entire argument here is the false notion that I've told a lie and the logical next step is that I must have falsified the photos I took of the temperature readings (something you basically accused me of doing when you mistook the soundbar of my LG TV for the top of the Ghent case in one of the pics) or that I'm just measuring wrong with the intent of fooling myself into remaining happy with my purchase. I can assure anyone still following this shitshow that that's not the case.

And yes, I do recommend this product if the build quality stays as high or gets better. From what I've seen, including your own bad experience with them, that isn't a given. However, I also qualified it from the very beginning that my recommendation carried a condition "at this price." You'd have a hard time getting all the modules, wiring and a case for less than VTV sent me one already assembled. Technically "you" (or any of us non approved OEM vendors) *can't* build such a product at ANY price given the restrictions Hypex has in place.

Good night to you as well, and this won't be my last post on this thread. I'm looking for a good cheap thermal camera as we speak.

 

[TimF]

This Thread is Most Pertinent. The Issue Under Discussion Should be Worked Out.
There is agreement that at a certain point (temperature) heat is detrimental to audio equipment. Heat is generated by audio electronics and in various ways it is managed including vents, heat sinks/fins, fans. There have been credible posts on ASR of class D amp modules being damaged to the point of failure from heat. The damage and failures addressed in these ASR posts seems to be from continuous operation at high temperature rather than from high temperature spikes. There is general if not complete agreement in this thread, as well as in other ASR threads, that heat is an issue with class D amps and should/must be considered and managed with Hypex amp modules. I assume the same is true with Purifi modules. Let us not argue--instead let us work together to develop a couple recommendations on effective build options to manage heat in aluminum chassis' housing Hypex modules. Can we agree that under the current standard build practice of the major retailers of Hypex amps that there is likely and prevailing inadequate or barely adequate heat management. We'd all like to see a simple solution going forward. Can we all agree that if a simple change in prevailing design would bring benefits in heat management that it should be implemented. And all the better if it could be easily implemented or added to all the amps out in the real world today. Now for my stupid questions. Would it do any good to increase the height of the feet on the amp to increase effective air circulation to the bottom plate? Would installing heat sink/fin to the underside of the bottom chassis plate do any good at heat management assuming that the height of the feet would also be increased? Would it be beneficial or actually counter-beneficial to drill more holes and vents in the bottom plate of the chassis under the amp module? If we see high failure rates in Hypex amp modules due to excessive heat then we know the issue cannot be ignored. Would this be a solution going forward: should the amp module be mounted upright so that a heatsink can be attached to the bottom plate of the amp module, and implement that in conjunction with that additional generous vents be made in the chassis? I assume a solution would also be to increase the height of the chassis and add a heatsink to the bottom of the amp plate, install the amp module on the bottom plate of the chassis but make sure there is very very generous venting directly below the amp plate and its heat sink. Do downward facing heat sinks work if adequately vented? $2.00 for the best suggestion going forward. Let's not punish and tear apart the existing companies who all probably have weaknesses in their implementations. I have many weaknesses in my implementation.

 

[BlackTalon]

A good cheap thermal camera is $4k-5k. Anything less is a toy

 

[C. Cook]

A good cheap thermal camera is $4k-5k. Anything less is a toy

As is true with most things, I guess. :-(

I ended up getting a cheap (<$350) Android FLIR on Amazon and it gets here tomorrow.

 

[C. Cook]

This Thread is Most Pertinent. The Issue Under Discussion Should be Worked Out.
There is agreement that at a certain point (temperature) heat is detrimental to audio equipment. Heat is generated by audio electronics and in various ways it is managed including vents, heat sinks/fins, fans. There have been credible posts on ASR of class D amp modules being damaged to the point of failure from heat. The damage and failures addressed in these ASR posts seems to be from continuous operation at high temperature rather than from high temperature spikes. There is general if not complete agreement in this thread, as well as in other ASR threads, that heat is an issue with class D amps and should/must be considered and managed with Hypex amp modules. I assume the same is true with Purifi modules. Let us not argue--instead let us work together to develop a couple recommendations on effective build options to manage heat in aluminum chassis' housing Hypex modules. Can we agree that under the current standard build practice of the major retailers of Hypex amps that there is likely and prevailing inadequate or barely adequate heat management. We'd all like to see a simple solution going forward. Can we all agree that if a simple change in prevailing design would bring benefits in heat management that it should be implemented. And all the better if it could be easily implemented or added to all the amps out in the real world today. Now for my stupid questions. Would it do any good to increase the height of the feet on the amp to increase effective air circulation to the bottom plate? Would installing heat sink/fin to the underside of the bottom chassis plate do any good at heat management assuming that the height of the feet would also be increased? Would it be beneficial or actually counter-beneficial to drill more holes and vents in the bottom plate of the chassis under the amp module? If we see high failure rates in Hypex amp modules due to excessive heat then we know the issue cannot be ignored. Would this be a solution going forward: should the amp module be mounted upright so that a heatsink can be attached to the bottom plate of the amp module, and implement that in conjunction with that additional generous vents be made in the chassis? I assume a solution would also be to increase the height of the chassis and add a heatsink to the bottom of the amp plate, install the amp module on the bottom plate of the chassis but make sure there is very very generous venting directly below the amp plate and its heat sink. Do downward facing heat sinks work if adequately vented? $2.00 for the best suggestion going forward. Let's not punish and tear apart the existing companies who all probably have weaknesses in their implementations. I have many weaknesses in my implementation.

Yes, I agree. Through the course of this thread the bigger picture emerged to me as well. There are probably numerous commercially available cases/cabinets/chassis/whatever that - alone without added treatment of some kind - are not conducting enough heat away and dissipating it so as to maximize component lifespan. Although it was only alluded to, it sounds like someone actually did some measurements on Ghent's case and decided not to use it due to inadequate heat dissipation for a particular nc500 based configuration. Or I could be reading what was said wrong and it was just calculations (such as Mr. Mojo has provided above) that show there are several Ghent cases that are not suitable for the Hypex products they're being marketed for. I've found that IcePower's AS series doesn't generate nearly as much heat as Hypex nc modules or SMPS. The nc502mp that I've got also doesn't generate as much.

But when I get more time away from work, I'll be putting together a workshop out in the garage. I've never had space enough at our previous homes. That will give me the incentive and room to really start tinkering again and hopefully I'll learn something new and get some nice tools in the process. ;-)

 

[BlackTalon]

As is true with most things, I guess. :-(

I ended up getting a cheap (<$350) Android FLIR on Amazon and it gets here tomorrow.

We experimented with one of those a couple years ago (the iPhone version). Size and weight were convenient, but it was fairly buggy and crashed/ froze a lot. Some of that may have been due to the connector in the phone, as it was a phone that was no longer in regular service (my business partner had recently upgraded). We went with a real meter about 6 months ago; there is no comparison. Way, way, way more capable and it's rock solid. Definitely hits you in the wallet, though.

 

[C. Cook]

We experimented with one of those a couple years ago (the iPhone version). Size and weight were convenient, but it was fairly buggy and crashed/ froze a lot. Some of that may have been due to the connector in the phone, as it was a phone that was no longer in regular service (my business partner had recently upgraded). We went with a real meter about 6 months ago; there is no comparison. Way, way, way more capable and it's rock solid. Definitely hits you in the wallet, though.

I only spend $4K-$5K on good speaker wires. Just kidding. That's insane; I hope you have a return on investment baked into that purchase. Which one did you get? Sorry if you already told me, it's late.

 

[BlackTalon]

I only spend $4K-$5K on good speaker wires. Just kidding. That's insane; I hope you have a return on investment baked into that purchase. Which one did you get? Sorry if you already told me, it's late.

I'll have to dig it up at work. We looked at quite a few of them. It's not a Flir or Fluke. It will aid our building envelope diagnostics. We already have nuke meters for roofs and capacitance meters. Payback will likely take a few years, as it won't be used very often.

 

[C. Cook]

I'll have to dig it up at work. We looked at quite a few of them. It's not a Flir or Fluke. It will aid our building envelope diagnostics. We already have nuke meters for roofs and capacitance meters. Payback will likely take a few years, as it won't be used very often.

Well, crap. So they weren't able to locate the Flir that I ordered and now it's apparently on backorder. Ended up getting one of these. I may just take some pictures for a day, send it back and buy a better one later.

https://www.amazon.com/gp/product/B07RR6WGY3/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

[Rick Sykora]

May have missed, but have you contacted VTV and/or Ghent and asked them whether they checked their thermal designs?

 

[C. Cook]

May have missed, but have you contacted VTV and/or Ghent and asked them whether they checked their thermal designs?

Yeah I reached out to Ghent twice. No response either time so based on that and the fact that they are selling essentially the same case design for a wide range of Hypex and IcePower (possibly others) class D amps, I'm guessing no thermal analysis went into the design, especially not for each different application he's marketing them for. Wish I was wrong about that, but I think it's accurate.

I *highly* doubt that VTV did much in that regard either, but who knows. He's using the standard Ghent cases with customized faceplates as are a few other builders that I've run across.

All in all, I think this could be a big deal with so many Hypex OEM resellers not really doing anything special at all where heat sinking is concerned, but at the same time, it seems like Hypex would take an interest in their approved OEM sellers putting the modules in adequately heat sinked cases and would've communicated any concerns. Again, though, who knows.

 

[Rick Sykora]

Yeah I reached out to Ghent twice. No response either time so based on that and the fact that they are selling essentially the same case design for a wide range of Hypex and IcePower (possibly others) class D amps, I'm guessing no thermal analysis went into the design, especially not for each different application he's marketing them for. Wish I was wrong about that, but I think it's accurate.

I *highly* doubt that VTV did much in that regard either, but who knows. He's using the standard Ghent cases with customized faceplates as are a few other builders that I've run across.

All in all, I think this could be a big deal with so many Hypex OEM resellers not really doing anything special at all where heat sinking is concerned, but at the same time, it seems like Hypex would take an interest in their approved OEM sellers putting the modules in adequately heat sinked cases and would've communicated any concerns. Again, though, who knows.

Likely you are right although Hypex uses a Ghent cases for their diyclassd.com kits. So am less worried about single module kits. As has been pointed out, there is likely a point where the case alone is not enough to dissipate the heat. I have NC500 monoblocks and they have never gotten very warm. TBH, have not stressed them much either.

 

[goryu]

has anyone with this VTV nc1200 stereo amp bothered to check into the input and output wiring connections to check whether or not VTV inverted the wiring to one channel? The Hypex power supply they use is not recommended to be used with half bridge modules, like the nc1200, due to power supply pumping issues unless one channel has inverted input and output. Reading of past issues here with VTV, I can't help but wonder if they were aware of this necessity. I bought a used VTV nc1200 stereo amp and my inputs were not inverted. Anyone else?

According to Apollon, a hypex module amp seller:

"the Hypex SMPS3K power supplies do not feature the 2-quadrantoperation as most other Hypex SMPS power supplies do. Therefore, they are unable to handle large reverse currents generated by half-bridge amplifiers operated at low frequencies. For this reason, it is not advisable to use the Hypex SMPS3K to power half bridge amplifiers like the NC500, NC1200 and Purifi 1ET400A modules when used in the frequency range below 100Hz. This is the main reason why the difference in bass performance when using the 3800 watt power supply with half bridge class d modules is so audible. ...The only way how to solve this was adding a second half bridge class d module to the 3800 watt power supply and putting the second module out of phase or bridging both half bridge class d modules."

 

[C. Cook]

has anyone with this VTV nc1200 stereo amp bothered to check into the input and output wiring connections to check whether or not VTV inverted the wiring to one channel? The Hypex power supply they use is not recommended to be used with half bridge modules, like the nc1200, due to power supply pumping issues unless one channel has inverted input and output. Reading of past issues here with VTV, I can't help but wonder if they were aware of this necessity. I bought a used VTV nc1200 stereo amp and my inputs were not inverted. Anyone else?

According to Apollon, a hypex module amp seller:

"the Hypex SMPS3K power supplies do not feature the 2-quadrantoperation as most other Hypex SMPS power supplies do. Therefore, they are unable to handle large reverse currents generated by half-bridge amplifiers operated at low frequencies. For this reason, it is not advisable to use the Hypex SMPS3K to power half bridge amplifiers like the NC500, NC1200 and Purifi 1ET400A modules when used in the frequency range below 100Hz. This is the main reason why the difference in bass performance when using the 3800 watt power supply with half bridge class d modules is so audible. ...The only way how to solve this was adding a second half bridge class d module to the 3800 watt power supply and putting the second module out of phase or bridging both half bridge class d modules."

I'll definitely check this (I'm the OP) when I get a chance to open it up again. Either way, from that it would appear that the PS VTV is using in this build is not applicable/unsound in that configuration. I will say I've had no problems whatsoever with the unit in the time since this thread died down and I use the amp every day for home theater use, just two speakers L/R and bass performance is pretty incredible without a subwoofer. Don't notice any distortion, but with bass primarily in movies that would obviously be tricky. Sounds excellent with music too, though.