The New Hypex Fusion Plate amps

[Frank207be]

@IamJF thanks a lot for the offer. As soon as I buy the Hypex Fusion and I have all speaker chassis (I already bought Purifi PTT6.5M08-NFA-01 last year) and cabinets ready, I'll let you know.

 

[YSDR]

The missing Wima caps for the NC252MPs (woofer and mid channel of the FA253) are arrived, I replaced them, they are working but something went wrong. The tweeter channel of one amp sizzles relative loudly for about 1 sec and only after a cold start, when the amp is not warmed up. After that it not sizzles and works normal in silence. It doesn't sizzles if the amp is warm at the start.
It's not the tweeter channel amp failure, because I swapped them. So something on the NC252MP board but coming out on the tweeter.

What this can be?
Maybe bad SMPS cap(s) for the tweeter channel?

 

[YSDR]

It looks like it's probably a bad solder joint on one Wima cap, I'll try to fix it.

 

[uncola]

Any news about fusion plate amps being updated with ncorex?

 

[YSDR]

I use these amps for near field speakers and there is always a "tonal" component to the remaining noise (which you hear on a midrange dome cause of high sensitivity).

BTW which low-pass film caps your amps have? The blue (Epcos) or the brownish ones (cheap Chinese)?

My amps is at a professional repairer because I burned off a solder point at one of the film caps leg. I find that de-soldering through-hole parts on this Hypex board is a pain.

 

[Juhazi]

One of my first pair of FA123 died. It is labelled 3818 and has been practically all the time powered since December 2018. Power shuts up soon after start, no sound and no connection with HFD.

The project is here, made for my daughter https://www.diyaudio.com/community/threads/seas-mr18-3-way.322839/

The mistake I made was that the amp didn't have enough ventilation. I changed it a two years younger unit from another pair from 2020 and tried to make vents to breath better. Now waiting tosee how long the other unit lasts...

 

[YSDR]

One of my first pair of FA123 died. It is labelled 3818 and has been practically all the time powered since December 2018. Power shuts up soon after start, no sound and no connection with HFD.

It's quite possible that you have a capacitor failure. The caps of the Fusionamps are cheap Chinese ones, not even long-life units. Shame on Hypex, but that's how busines works nowadays, cheaping out on the manufacturing or parts, no matter if the product not lasts long. Of course the failure can be due improper use. Did you do this?

 

[Juhazi]

I can't see a popped cap, the problem apperared when the unit was started after being shut down for a week. Most likely problem is on transformer board. Warranty is over, I will try to find a new part. I can't do any component measurements or change them myself. But because of modular system, I can change a module myself.

 

[Juhazi]

Ah, the SMPS is integrated to NC122MP board. It feeds power to NC100HF too

https://www.hypex.nl/products/amplifier-families/mains-powered-ncore-family/nc122mp-oem
https://www.aliexpress.com/item/1005004465037184.html

 

[YSDR]

I can't see a popped cap, the problem apperared when the unit was started after being shut down for a week.

Still can be due to bad cap(s), IMO. They sat uncharged for a week, and it's possible that their error came from that, because they was worn already.

 

[YSDR]

Here is a similar (and solved) case:

https://www.diyaudio.com/community/threads/2-x-hypex-smps1200-dead-following-power-cut.374965/

 

[Juhazi]

I swapped the other speaker's FA123 too. Then I noticed the difference in PCB and component layout between 2018 and 2020 boards! The brown resistor is missing in 2020. As well NC100HF pcb is different but components look similar. The broken 2018 batch unit on left in both pics.




These were my first speakers with FAs. I was hurrying because of Christmas and believed that classD will not get hot, so I covered the plates with fabric and didn't check vents...





The inspiration and diy...

 

[Gerwin Göttlich]

Is it ok to match a 8 Ohm woofer with a 4 Ohm coax driver on a FA 253, or does it has any downsides?

 

[YSDR]

No problem at all combining different impedance drivers.

 

[Kruger]

Does anyone have an idea how much power can be consumed from the NC122MP channel extension power output ?
https://www.hypex.nl/media/65/89/0d/1708504145/NC122MP_04xx_R16.pdf

The interface, that powers the NC100HF amplifier.
https://www.hypex.nl/media/b0/4a/69/1708608357/NC100HF_04xx_R8.pdf

 

[IamJF]

These modules are limited to 100W but can put out more peak level. It looks like the limit is from the power supply and heat design.
So I would for sure not use more as 100W from this supplies.

 

[Kruger]

100W peak and 20W continuous cover the NC100HF spec.
Can more than 20W continuous be (relatively safely) consumed. I have to test.

 

[IamJF]

I would ESTIMATE that the thermal limit of the amp module is 20Wrms but electrical 100W would be fine.
Best to ask Hypex, 20W or 100W is quite a difference!

 

[Kruger]

I connected 2 x 25 ohm resistors to channel extension power output pins 1, 2, 3, and left the FA123 module for a couple of hours.
The NC100HF power supply is 2x36.5V - so around 100W were constantly consumed. The space was relatively cold around 15°C.

Three zones became more hot. The TO220 conglomerate of BYQ28E diodes and IRF640 MOSFETs heated to 100°C.
The SCK-055 NTC reached 80°C. The rectifier on the upper right ~60°C.

And i got an answer to my question above. The NC122MP power supply is the same as the add on NC100HF module.
More than 20W can be consumed. I should have measured with ohmmeter.

 

[IamJF]

While 100°C is really a lot I regularly measure temperatures in this range for these active modules. They run pretty hot.
That's also why I'm pretty sceptical about these "put 8 channels Hypex in cramped spaces" multi channel amps - there will be crazy high spot temperatures, that's a pretty risky concept.