CurtPalme.com Home Theater Forum

[HK-Steve]

Yes, I got a better price from German dealer, than from a local dealer, Euro was better against the Swiss Franc.


Will ask at the German guy's first, then see what happens.


Appreciate your advice.

Cheers


PM also sent back to you.

[Nashou66]

Look's Like I am having the same Issue. I'll try the same as you did steve but I did contact Lumagen for a new supply.

Nashou

[Nashou66]

Cap was also bulged but I think the regulator went bad as well.

Damn it!!!

Nashou

[HK-Steve]

Yes, I got a new power supply, it is like a computer PS, not a wall plug pack.

No issues since.

[HK-Steve]

My original still works,
I can post it to you??

[Nashou66]

Thanks Stevebut thats OK, I'll wait for Lumagens answer and I want to build a Multi output linear power supply for all my wall warts. So one unit will handle the 8 wall warts I have.

But do you have a link to which one you bought? And what is the connector size I should look for if I go local store to buy one for now?

Athanasios

[HK-Steve]

Lumagen replaced it under warantee, no questions asked.

you need 5volts @ 5amps.

Cheers

[HK-Steve]

Well, looks like the replacement computer style power supply is now faulty, got the same problem again, grrrrr............

Going to pull it apart tomorrow, to see if it is the same as the original Wall wart.




Probably build a linear power supply.
But do not understand, as the XS+ only pulls 2amps, why do the 5amp units keep failing.


Cheers

[Nashou66]

[HK-Steve]

Thanks, saw a thread about the Sigma supply, have bookmarked it.
Looks like I will be building one.

I measured the power draw between 1.5 and 3amps. So the 5 amps seems well within it's capacity, IF, it really is rated correctly.
Will find out more tomorrow when I pull it to pieces,


Cheers

[HK-Steve]

This is the inside of the new power supply,



This is what I found, looks like in the manufacturing process, the capacitor has been pushed so the output cable could be positioned,
this has pulled the leg out of the capacitor,



I replaced the cap with a new one, all good so far with the Lumagen. Fingerscrossed, no other issues.


Cheers

[Nashou66]

Here is one of the Sigma 11's I built so far. The on board heat sinks are not enough as they get really hot. A fan would help, but i decided to do some quick fabricating and add more heat dissipation. What I will do on the next one is go to a larger off board heat sink once I find one I think will fit in the chassis I plan to use.

[CxTurbo]

Sweet!

I will need to get off my butt someday and build up mine too. As you said the heat sink will be the issue.

There was a guy on DIY Audio who was making heat sinks for some of the big class A amps from Pass. He was selling the on ebay for LED lighting as well. I'll see if I can find his name for you.

James

[Nashou66]

I saw some on Ebay. But I might just cut up a Marquee rear heat sink and try that. I also have an older HDM i could use that as well. Cut the HDM sink in half for each Mosfett. I think its best to keep them separated with their own heat sink.

Athanasios

[CxTurbo]

That might work too.

He sells on his website now. Heatsinkusa dot com.

If you do not try the Marquee one give a peek at what he has to offer.

[Nashou66]

I'll check it out but I think I should have gone with a slightly smaller transformer secondary output.
FOr a 5 volt out it is suggested to use a 9 volt secondary. I got the Hammond 185E20, with a supposed 10v out.
Well mine measures 11.3. I have a slight high AC voltage here about 124-126. SO I bet a Hammond 185E16 would be better as it has a 8 volt out.

I ran the Power supply for an hour and it the heat sink sides are hot to the touch( the main board mounted sections).

It says the heat junction temp for that chip is high but Id rather have it run cooler. Might have to order the smaller Transformer.
Now I'll have this lying around!. Unless there is way I can lower its secondary output easily?

Athanasios

[Nashou66]

Well I bought an IR thermometer to test the heat off the IRLZ24 Mosfett
http://www.irf.com/product-info/datasheets/data/irlz24n.pdf
And heat sink. The Junction Temp says it can operate up to 175c !! Thats HOT.

I measured the heat sink just above the chip and the chip it self and the range was from 45c-75c

So I think I'm Good. On my next Board I'll measure temp with out
the added Aluminum Bridge to the other heat sink and see how it fares.

I'm Running an HDQ right now on this. Dont want to blow up a radiance!



Athanasios

[Nashou66]

Thinking this over and The Guys at AMB.org say its still too hot.
So I went to the site you linked Heatsink USA and ordere two of these.

http://www.heatsinkusa.com/5-375-wide-extruded-aluminum-heatsink/




Product Description

Extruded Aluminum Heatsink

Width: 5.375"
Fin Height: 1"
Base: .375"
C/W/3": approximately 1.15
Weight per Inch: .37

The C/W is for 3" of the heat sink. The original heat sink was 21k sqr mm's about.

this will have over 93k sqr mm's if my calculations are correct for 3.5" length of it.

I plan to mount the Mosfet's on the under side of the PCB and mount them to the heat sink that way.
I'll face the heat sink fin up and the board will be upside down in the Chassis on tall stand offs.

Here you can see the bottom mount method




Both mosfet's will be connected to the single heat sink but since the area is almost 4 times larger I should still get better
cooling.

What do you think?

Nashou

[CxTurbo]

I can't see a problem with mounting them in the manner you describe. You could always add a fan to blow across them should you still have an issue. I think it would be better actually then to mount vertically. The heat sink in my mind should cool more uniformly versus being mounted vertically. That is just my logic though and I have not tested or played with it other then knowing a car amplifier with fins gets way hotter mounted vertical then if mounted flat.

James

[Nashou66]