NC400 Cooling

yetis · « **Reply #60 on:** 6 Jul 2012, 03:32 pm »

Before reading Bruno's comments, I didn't know what to make of the heat. I can tell you that I did NOT plan for the level of heat when selecting a case. Few of the cases available have any real cooling functions that are common on class A amps, etc. I find it interesting that other Class D amps don't seem to generate the same level of heat, so I wonder if that has something to do with its increased performance? Logic works in the class A/A-B/B amp performance. I guess the Halcro amps generate a fair amount of heat, but use cases to handle the heat they generate?

undertow · « **Reply #61 on:** 6 Jul 2012, 05:37 pm »

I used 3 heatsinks on each power supply that were recommended earlier in this thread with self adheasive and designed to lay horizontally. They fit perfect, they go right on the super hot plates of the SMPS and they cool to such a level you can easily now lay your hand across the entire power supplies with no real heat left over. Very nice for about 8 bucks! The NC400 is fine, it barely warms up even under heavy load.

And dare I say actually the performance seems better, I can crank with no frequency shifts and very consistent smooth sound. I have a case much taller than most here, actually my case is close to double the height most guys used so these heatsinks fit great, and they are air cooled via the vents on the top of my case with Zero issues now. They were running hotter than most amps, now they run much cooler than any other amps I had. Worth just putting a little effort in, I don't like the Cigar box style jam packed anyway, but thats just me. And I did have one SMPS go bad in the first week so they did replace it and if you plan on leaving these amps on 24/7 I suggest sufficient cooling. Of course I did run DUAL mono so they are in one case where others are using them in 2 smaller cases and likely do not get quite as hot.

genjamon · « **Reply #62 on:** 6 Jul 2012, 06:28 pm »

Strange. Sounds like some report the SMPS as being the main source of heat, while others have found the amp modules to be hotter. My SMPS don't get nearly as hot as my amp modules, and that's in open air, without chassis top cover installed. I do keep my house at about 80 or 82 degrees during these summer months, but still...

I used silver thermal compound between amp modules and and an all aluminum chassis.

My measurement of power draw is that SMPS draws 13 watts at idle, and amp module another 5 watts when mute is disabled. I would think the SMPS would then be the hotter element. Not sure why not in my case.

undertow · « **Reply #63 on:** 6 Jul 2012, 06:34 pm »

Well keep in mind the NC400 is to a whole chassis normally and your just running on an open plate with no sides which could be worse as thats your heatsinks...

Mine have heatsink sides as well always attached the plate that the NC400 is bolted, the issue with the SMPS is that it just radiates off the top of the plates with nothing bolted to it. And my opinion is that the heat generated off the SMPS is just trapped in the chassis heating the NC400 up even more. But with the SMPS heat sinked all across the top plates, it seems very cool overall now period.

genjamon · « **Reply #64 on:** 6 Jul 2012, 06:51 pm »

No, mine have side and rear plates installed as well. No front or top plates last time I checked the heat issue, although now they are completely assembled. The guy who measured with calibrated equipment seemed to have the same situation as me, if I recall correctly. I don't have time right now to look back for that post and double check.

mjosef · « **Reply #65 on:** 6 Jul 2012, 08:27 pm »

"Do as I say, not as I do"?

Here is a pic of Hypex NC1200 demo unit...nicely vented.

http://www.6moons.com/industryfeatures/ncore/1.html

undertow · « **Reply #66 on:** 6 Jul 2012, 08:35 pm »

Well venting is a no brainer in my opinion, as well as these are fairly tall cases compared to most I have seen literally some giving no more than a 1/4" or so above the board in airspace. Those are about the height of my dual mono if you see the photos earlier in this thread and they give a good 1.5 to 2" of space and good 360 degree circulation. These are just as good or better because its 2 chassis and full venting from all corners getting really good airflow and has nice height.

mgalusha · « **Reply #67 on:** 6 Jul 2012, 08:39 pm »

Quote from: mjosef on 6 Jul 2012, 08:27 pm

"Do as I say, not as I do"?

Here is a pic of Hypex NC1200 demo unit...nicely vented.

Indeed and the SMPS1200 in those is heat sinked to the chassis, so that would help a lot as well. The data sheet shows a large sink that is the full size of the board, would be nice if the SMPS600 used the same design but alas no.

genjamon · « **Reply #68 on:** 6 Jul 2012, 09:04 pm »

I just wanted to underscore that I'm not really worried about the heat issue, at least in my implementation. I would worry about putting them in really tight chassis, with materials that don't allow heat to escape well, etc, but that's not my situation. Mine are good size, all aluminum, and vented on the top plate.

I'm really just interested in getting a firm grip on what the power and heat parameters really are in the real world. Also I'd like to know if I should make any adjustments of my own to further optimize. Those CPU heatsinks could be really handy, but the SMPS doesn't seem to be the problem child for me that it is for others. Would it make sense for me to apply those heatsinks to the electrolytic caps on the modules? That's where it's hottest right now in my implementation, and where the highest heat seemed to be in the calibrated measurements several posts ago.

Or maybe I don't have my modules coupled properly to the chassis after all? I mean, I think they're pretty firmly physically connected, but maybe there's a slight physical gap? Or maybe that silver thermal compound doesn't work as well as they say, and I actually created more of a barrier to thermal conductivity by using it?

undertow · « **Reply #69 on:** 6 Jul 2012, 09:22 pm »

I did adjust the DC offset on the input and outputs of the NC400 to virtually perfect "Zero", but I doubt this has too much to do with your caps getting hot. Mine were only out of whack by very few millivolts anyway.

genjamon · « **Reply #70 on:** 6 Jul 2012, 09:31 pm »

Well, that's true. I haven't checked DC offset yet. Should look into that next.

mr_bill · « **Reply #71 on:** 6 Jul 2012, 09:57 pm »

Quote from: mjosef on 6 Jul 2012, 08:27 pm

"Do as I say, not as I do"?

Here is a pic of Hypex NC1200 demo unit...nicely vented.
http://www.6moons.com/industryfeatures/ncore/1.html

Now those are nice silver face plates. Would like to add a blue led to mine and would love to be able to engrave or silkscreen the logo - smaller like that.

Steidl Guitars · « **Reply #72 on:** 6 Jul 2012, 11:34 pm »

Quote from: mr_bill on 6 Jul 2012, 09:57 pm

Would like to add a blue led to mine

Bill, that's pretty straightforward. You need only an LED, a resistor, some solder, and a drill bit.

The PS comes with a set of wires that connect to the auxiliary supply provided; I think the set has 5 or 6 black wires, and you need only two of those (but the right two!).

Solder the + lead from the PS to one leg of the resistor, then solder the other leg to the + side of the LED. Next, solder the - lead from the PS to the - side of the LED.

You can determine the value of the resistor you need based on the voltage provided by the PS (21v I think?) and that required and sent forward by the LED; there are on-line calculators that make that easy to do once you have the specs from the LED you select.

Then it's just a matter of mounting the LED into the face plate, which is usually just drilling a hole that's sized appropriately and stuffing it in.

Atlplasma · « **Reply #73 on:** 7 Jul 2012, 12:51 am »

Quote from: undertow on 6 Jul 2012, 05:37 pm

I used 3 heatsinks on each power supply that were recommended earlier in this thread with self adheasive and designed to lay horizontally. They fit perfect, they go right on the super hot plates of the SMPS and they cool to such a level you can easily now lay your hand across the entire power supplies with no real heat left over. Very nice for about 8 bucks! The NC400 is fine, it barely warms up even under heavy load.

And dare I say actually the performance seems better, I can crank with no frequency shifts and very consistent smooth sound. I have a case much taller than most here, actually my case is close to double the height most guys used so these heatsinks fit great, and they are air cooled via the vents on the top of my case with Zero issues now. They were running hotter than most amps, now they run much cooler than any other amps I had. Worth just putting a little effort in, I don't like the Cigar box style jam packed anyway, but thats just me. And I did have one SMPS go bad in the first week so they did replace it and if you plan on leaving these amps on 24/7 I suggest sufficient cooling. Of course I did run DUAL mono so they are in one case where others are using them in 2 smaller cases and likely do not get quite as hot.

I'm considering a similar strategy. Would you mind posting a picture?

PeteG · « **Reply #74 on:** 7 Jul 2012, 01:26 am »

Here’s a picture testing my Ncores (in my garage) after a couple of changes and adding some silver thermal compound for the NC400 and some venting on the top plate for the PS, might add heat sinks later if I need them but I doubt it. Now no more worries for me about heat.

yetis · « **Reply #75 on:** 7 Jul 2012, 07:09 am »

Quote from: genjamon on 6 Jul 2012, 09:04 pm

I just wanted to underscore that I'm not really worried about the heat issue, at least in my implementation. I would worry about putting them in really tight chassis, with materials that don't allow heat to escape well, etc, but that's not my situation. Mine are good size, all aluminum, and vented on the top plate.

I'm really just interested in getting a firm grip on what the power and heat parameters really are in the real world. Also I'd like to know if I should make any adjustments of my own to further optimize. Those CPU heatsinks could be really handy, but the SMPS doesn't seem to be the problem child for me that it is for others. Would it make sense for me to apply those heatsinks to the electrolytic caps on the modules? That's where it's hottest right now in my implementation, and where the highest heat seemed to be in the calibrated measurements several posts ago.

Or maybe I don't have my modules coupled properly to the chassis after all? I mean, I think they're pretty firmly physically connected, but maybe there's a slight physical gap? Or maybe that silver thermal compound doesn't work as well as they say, and I actually created more of a barrier to thermal conductivity by using it?

I agree. I just wish my preconceived view of class D wasn't so wrong. To think my Pass Amps only ever generated this sort of heat when they were on! I will need to make some adjustments to my case, certainly some venting is in order. My biggest issue is their placement.

genjamon · « **Reply #76 on:** 8 Jul 2012, 01:16 am »

I adjusted the DC offsets last night. They definitely needed it. The output was off by a couple hundred millivolts on each amp, inputs by only around 20.

Unfortunately, the heat didn't seem to change.after the eveningg with everything on, I did find the SMPS plates to be as hot as the modules. The cases were also pretty warm, definitely conducting quite a bit of heat. I'm thinking those CPU heatsinks are definitely in order. I'm also beginning to suspect that part of the issue is how warm I keep things in summertime.

ufokillerz · « **Reply #77 on:** 30 Jan 2013, 02:35 pm »

sorry to bump this thread, i've had my ncores for short of 2 months now, the cases they are in are only 6mm taller then the psu heatsinks internally. i have them bonded to the top lid with thermal pads. my case is also sealed with NO vents. My cases are all aluminum, but do not have heatsink fins for dissipation.

i wanted to see if anyone with the amps for a much longer time then me have experienced any issues yet. I figured since its only been 2 months, i mind as well check in with others, if there are problems then i still have time to rectify it.

jtwrace · « **Reply #78 on:** 30 Jan 2013, 03:49 pm »

Quote from: ufokillerz on 30 Jan 2013, 02:35 pm

sorry to bump this thread, i've had my ncores for short of 2 months now, the cases they are in are only 6mm taller then the psu heatsinks internally. i have them bonded to the top lid with thermal pads. my case is also sealed with NO vents. My cases are all aluminum, but do not have heatsink fins for dissipation.

i wanted to see if anyone with the amps for a much longer time then me have experienced any issues yet. I figured since its only been 2 months, i mind as well check in with others, if there are problems then i still have time to rectify it.

No issue. Bruno says it's fine.

ufokillerz · « **Reply #79 on:** 30 Jan 2013, 04:41 pm »

Quote from: jtwrace on 30 Jan 2013, 03:49 pm

No issue. Bruno says it's fine.

Thanks, i read the post by Bruno, but it doesn't hurt to see if anyone might have had failures due to heat. i mean right now my amps are like little heaters, but i just love the compact size of mine, they take up like no space!