Hypex NC252MP Overheating?

[Buckeye Amps]

Thinking about this some more, and noting the temperature of the bottom plate of the case, I think it might make more sense to buy some finned heat sink extrusion and attach it to the bottom of the case. <---Edit: While playing music. I'll add the standby switch for idle time.

As Rick said, because of how thick the front panel is, you can easily add a switch on the bottom of the case up front or along the back panel (if reaching behind isn't an issue).

It also isn't hard to add a 12v trigger, I just don't have it as an option for the Ghent case because without also adding a standby switch, a customer would be SOL if the trigger ever failed. So I kind of leave it up to the customer to modify it. Another reason I can usually fill a Ghent case order quickly vs. my current build schedule for my amps.

 

[YouCanCallMeGeorge]

Would not waste your time or money. Likely this module is defective and should be under warranty.

Unless you think you caused it to be damaged, get it replaced. If you prefer to discuss more discretely, PM me and will help as best I can.

Rick

I'm sure the temperature while idling could not have damaged the amp. Whether the temperature while active could be damaging, I don't know. I suppose I can put the cover back on, run the system for a couple of hours, and see how hot it gets. On the other hand, if we start with the fact that many copies of this amp and case have been sold and mine is the only known failure, then it can be argued that it is the amp module that is the problem, not the case.

I have done nothing to damage the amp that I know of. There is a two inch gap between the top of the case and the preamp above, and at least a foot of gap on all sides, so airflow is not an issue. There has never been a static discharge on the case, or on any of the connected components. There has been the slight pop of the MiniDSP SHD preamp at power up, but the preamp is a solid state unit and (I suppose) unlikely to pump a big shot of energy to the amp. Besides, I always turn the gain down to -40 before power down. (I've only forgotten once, that I can recall.)

How would I go about making a warranty claim?

 

[Buckeye Amps]

I'm sure the temperature while idling could not have damaged the amp. Whether the temperature while active could be damaging, I don't know. I suppose I can put the cover back on, run the system for a couple of hours, and see how hot it gets. On the other hand, if we start with the fact that many copies of this amp and case have been sold and mine is the only known failure, then it can be argued that it is the amp module that is the problem, not the case.

I have done nothing to damage the amp that I know of. There is a two inch gap between the top of the case and the preamp above, and at least a foot of gap on all sides, so airflow is not an issue. There has never been a static discharge on the case, or on any of the connected components. There has been the slight pop of the MiniDSP SHD preamp at power up, but the preamp is a solid state unit and (I suppose) unlikely to pump a big shot of energy to the amp. Besides, I always turn the gain down to -40 before power down. (I've only forgotten once, that I can recall.)

How would I go about making a warranty claim?

It wouldn't hurt to reach out to Rick through PM first. Otherwise for modules still under warranty I have sold, I would just have you send the module back and I will send you a new one. Hypex doesn't cover shipping costs so it is easier for me to just send back faulty modules under warranty in one batch. And it provides my customers with minimum downtime.

 

[YouCanCallMeGeorge]

It wouldn't hurt to reach out to Rick through PM first. Otherwise for modules still under warranty I have sold, I would just have you send the module back and I will send you a new one. Hypex doesn't cover shipping costs so it is easier for me to just send back faulty modules under warranty in one batch. And it provides my customers with minimum downtime.

Let's do it that way, since I bought the unit from you. (I appreciate the service.) But...I will wait a couple of days because I'm expecting six acoustic panels tomorrow and can't wait to see what effect they have. (Six 48x24x4 open back panels for a 12x12 ft room.)

 

[Buckeye Amps]

Let's do it that way, since I bought the unit from you. (I appreciate the service.) But...I will wait a couple of days because I'm expecting six acoustic panels tomorrow and can't wait to see what effect they have. (Six 48x24x4 open back panels for a 12x12 ft room.)

Just PM me when ready

 

[peng]

There has been the slight pop of the MiniDSP SHD preamp at power up, but the preamp is a solid state unit and (I suppose) unlikely to pump a big shot of energy to the amp. Besides, I always turn the gain down to -40 before power down. (I've only forgotten once, that I can recall.)

How would I go about making a warranty claim?

Slight pops can be considered normal depending on how one defines "slight" I suppose, but do you not always turn the power amp off first before turning off the preamp regardless of the volume setting? As others mentioned, it's just good practice to turn power amp off first and turn it on last.

 

[YouCanCallMeGeorge]

Slight pops can be considered normal depending on how one defines "slight" I suppose, but do you not always turn the power amp off first before turning off the preamp regardless of the volume setting? As others mentioned, it's just good practice to turn power amp off first and turn it on last.

I was turning the entire system on and off using the one switch on the power strip. Going forward I will put the amplifier in standby mode before powering down, and take it out of standby mode after all other components are in stable operation.

 

[YouCanCallMeGeorge]

Off topic, but worth mentioning: The six sound absorbing panels from ATS Acoustics arrived today. Build quality is excellent. I have the panels propped up very close to final positions. I listened to three songs, two of which caused obvious problems with shrillness in soprano vocal range and muddled bass. I listened with and without the panels in place. There is no question about the improvement; "dramatic" is not an excessive description. I think more could be done to improve the sound, particularly the bass, but I can say for sure that the system sounds much better without the Dirac filter than with it. Vocalists seem to be present in the room. And so on.

The panels are 48x24x4, rock wool, with open backs. If needed, I can extend the backs two inches and add another layer of rock wool. Six inches of rock wool is quite effective in the low bass range, according to the charts. I may also add some absorption on the ceiling at the early reflection points—but holes in the unpainted ceiling are not so easily hidden as holes in the painted drywall, when it comes time to take the panels down.

 

[YouCanCallMeGeorge]

Update: @Buckeye Amps sent a replacement amplifier module within 24 hours of my request. Excellent service.

 

[TheBatsEar]

Is the inrush pop there when you come from power off to on or from standby to on? Why do we still have devices with inrush pop in 2022?

If it's the latter, i think 0.12W standby is not much. If you leave it in standby for a year, you have to pay one kWh, which costs 0.35€ here. Not sure what one can buy for that, but it's not much.

These modules are, as @restorer-john wrote, designed badly, the manufacturer must be aware of this now. You just don't flex your PCB in that way. Best to consider those modules short lived. Most modules will probably fail after the first year, so that's not a problem for the manufacturer.

 

[Buckeye Amps]

I definitely wouldn't consider the modules "short lived" or that most "will probably fail after the first year". Unless I am missing a substantial amount of owners over the last 5 or so years who have had reported this exact issue?

 

[TheBatsEar]

I definitely wouldn't consider the modules "short lived" or that most "will probably fail after the first year". Unless I am missing a substantial amount of owners over the last 5 or so years who have had reported this exact issue?

Fair enough, "will probably fail after the first year" was a tad harsh.
You don't see the problem with using the PCB to keep pressure on the heattransfer pad?

 

[howard416]

The issue I highlighted, is the module design in that localized area. No amount of heatsink compound on the plate will help.

Once the board has flexed, it stays flexed and the pressure on the devices to maintain adequate thermal contact is reduced. The flexing of the PCB will place undue stress on any SMD components laying across the curve/flex- they may also fail in time due to cracking or solder joint failure. PbFree solder is hardly renowned for its flexibility.

The same mounting method is used around the output devices, but there are 5 screws in close proximity to the packages. There is less opportunity for the PCB to bend.

There's really nothing that you can do, the board needs a redesign with correct mounting methods for the devices in question. No PCB should be pressed into service (pun intended) as a device-to-heatsink clamp.

When in standby, those MOSFETs should not be running hot- the auxilliary supply standby switches on the main supply. The auxilliary supply shouldn't run hot. You can potentially prolong the life by unplugging the amplifier when not in use.

What about adding an additional clamping bracket on top where the PCB flexes the most? Only issue is, it would have to press down on top of the transformer since there's no other space on the PCB to press onto, practically speaking. Would this cause the transformer over time to fail? Or perhaps its solder joints?

 

[howard416]

Alternately, flipping the whole thing over and then mounting individual heatsinks for each area of equal height.

 

[RickS]

It is now 3 years after the OP here and as always, the question should be "what problem are we trying to solve"?

Have we been flooded with more failures since? Do any later generation Hypex/Purifi products take a different design approach? When I look at Nilai or Purifi's latest modules, have they abandoned the allegedly faulty board/heatplate approach? Not that I have seen.

Both companies have experienced engineers, and the basic mechanical design continues to be used. Unless you have experience and can show a potential mod improves the design, you might just as likely fix an "obvious problem" and introduce another that makes matters worse.

 

[Jimbob54]

It is now 3 years after the OP here and as always, the question should be "what problem are we trying to solve"?

Have we been flooded with more failures since? Do any later generation Hypex/Purifi products take a different design approach? When I look at Nilai or Purifi's latest modules, have they abandoned the allegedly faulty board/heatplate approach? Not that I have seen.

Both companies have experienced engineers, and the basic mechanical design continues to be used. Unless you have experience and can show a potential mod improves the design, you might just as likely fix an "obvious problem" and introduce another that makes matters worse.

Agree. Looks like OP got satisfaction 3 years ago. Absent a flurry of new incidents related to this I'm locking it. Please PM me if it needs reopening.