Concerning CLR Discovery

[jay mitchell]

I see.

This got me curious so I looked at the documentation here: UcD250LP_OEM/UcD180LP_OEM which mentions an internal regulator for VDR in the absence of an optional external VDR - For the UcD250LP, seems to be a 15V VDR and for the UcD180LP a 12V VDR.

Hypex chose this route because the output devices are in a "totem pole" arrangement, so the negative MOSFET's gate voltage must be referenced to the negative supply rail rather than to circuit common. Rather than use a relatively inefficient linear regulator for the purpose, they could have either put a DC-DC converter in the amp module or provided the required voltage in the power supply.

 

[Richard_G]

I have now replaced the power supply in my original (pre-Neo, pre-MkII) CLR active wedge with the one Jay recommended in the OP. It was an easy DIY, as he said.

I haven’t measured the temperature (at least not yet). But after powering up the unit and leaving it on for 60 minutes, I have no problem comfortably leaving my hand in contact with the heatsink.

Thank you, @jay mitchell.

 

[AlbertA]

I ordered a couple of UcD250LP modules from eBay - they came straight from China - they looked new and worked fine.

On a couple of my old amp modules, I noticed that the nuts and screws holding the mosfet casings to the heatsink are rusted, any idea why?

 

[norminal]

I noticed that the nuts and screws holding the mosfet casings to the heatsink are rusted, any idea why?

Likely dissimilar metal corrosion.

 

[Zentman]

It was cool to touch after 30 minutes of idle. Will try later when I crank for 2 hours.

 

[jay mitchell]

On a couple of my old amp modules, I noticed that the nuts and screws holding the mosfet casings to the heatsink are rusted, any idea why?

I can't say. I've seen many of these power amp modules in CLRs, and none of the ones I've seen - including several with years of use - have shown the slightest hint of corrosion. It is definitely not bimetallic corrosion, or every one of the modules would be affected. My best guess is exposure of the fasteners at some time in their history to corrosive chemicals. It's not an ongoing problem; just replace the affected fasteners after thoroughly cleaning the surfaces they contact.

 

[jay mitchell]

It was cool to touch after 30 minutes of idle.

"Cool" is not gonna happen, even with MkII amp modules and power supply.

Will try later when I crank for 2 hours.

The additional heat generated by operating at high levels will be pretty similar between original and MkII versions. The only significant difference is at idle.

 

[Zentman]

"Cool" is not gonna happen, even with MkII amp modules and power supply.

The additional heat generated by operating at high levels will be pretty similar between original and MkII versions. The only significant difference is at idle.

Interesting. Gonna run it at idle for an hour with fan. Maybe the word cool was hyperbole. It wasn't warm though.

I had reported them the same in a prior post but the one from 2016s board change runs hotter than the one changed in 2023.

When I idle them both for 30 minutes they are close. After an hour of playing the 2023 seems OK to touch. The other is uncomfortably warm after 20-30 seconds but doesn't burn. It's most assuredly hotter.

 

[nikitasius]

they looked new and worked fine

the nuts and screws holding the mosfet casings to the heatsink are rusted

You have alu caps near heatsinks lol. Check if these caps aren't pissed around while they was heating by mosfets. Absolutely stupid design.

 

[jay mitchell]

Absolutely stupid design.

Were that truly the case, then many of the amp modules would have displayed the same corrosion. That they have not makes it clear that this is not the issue you claim it is.

How about you show us some examples of "absolutely not stupid design" for our enlightment? Maybe one of your designs?

 

[Mongillo19]

Were that truly the case, then many of the amp modules would have displayed the same corrosion. That they have not makes it clear that this is not the issue you claim it is.

How about you show us some examples of "absolutely not stupid design" for our enlightment? Maybe one of your designs?

Now you've done it. Expect an email by COB

 

[nikitasius]

How about you show us some examples

I attached one for you!
The fixation doesn't have a nickel layer

 

[nikitasius]

Also i advice you to google why:

• don't place alu caps near heatsinks
• don't place alu caps near tubes
• don't eat alu caps

 

[jay mitchell]

I attached one for you!
The fixation doesn't have a nickel layer

So, by your "logic," every, or at least very many, CLRs would have corroded fasteners that attach the FET bodies to heatsinks. And yet, the person who has probably examined the components of more CLRs from the field than anyone else, has never encountered the problem. One user has seen it, which would imply that his specific example was most likely exposed to some corrosive materials. IOW - pay close attention now - not a design issue.

Again, show us some examples of designs that, according to you, are not stupid. Or, better yet, just stop your idiotic trolling on a subject about which you are quite obviously ill-informed.

 

[ian_dissonance]

Excited to see where this goes.

 

[Karl Houseknecht]

On a couple of my old amp modules, I noticed that the nuts and screws holding the mosfet casings to the heatsink are rusted

So it's more than just one. Seems odd that BOTH would have been exposed the the same random thing.

 

[FractalAudio]

I ordered a couple of UcD250LP modules from eBay - they came straight from China - they looked new and worked fine.

On a couple of my old amp modules, I noticed that the nuts and screws holding the mosfet casings to the heatsink are rusted, any idea why?

View attachment 40494

Do you live near the ocean?

 

[paisleywookiee]

Also i advice you to google why:

• don't place alu caps near heatsinks
• don't place alu caps near tubes
• don't eat alu caps

So, by your "logic," every, or at least very many, CLRs would have corroded fasteners that attach the FET bodies to heatsinks. And yet, the person who has probably examined the components of more CLRs from the field than anyone else, has never encountered the problem. One user has seen it, which would imply that his specific example was most likely exposed to some corrosive materials. IOW - pay close attention now - not a design issue.

Again, show us some examples of designs that, according to you, are not stupid. Or, better yet, just stop your idiotic trolling on a subject about which you are quite obviously ill-informed.

 

[V|J]

I’m no CLR expert but have been repairing and building amps for over 35 years.

In my expert opinion, rust is usually caused by salt + moisture. May also be corrosive chemicals.

Again, not an expert, but close to one.

 

[jay mitchell]

So it's more than just one. Seems odd that BOTH would have been exposed the the same random thing.

Really? It seems odd to you that two amp modules in the same CLR "would have been exposed the the same random thing?" Those modules were screwed to the plate before the module was installed in the CLR during production, and they remained together on the plate ever since. It requires no stretch to think that whatever exposure caused the corrosion occurred after the modules were screwed to the plate and had a similar effect on both.