KGSSHV Carbon Build Thread

[bui501]

9 minutes ago, sorenb said:

....same source as for the other 10m90's in your build?

The original 10m90s’es were from mouser... that was on the psu boards that were (mostly) working before I melted the components by running them without proper thermal pads... all of the replacement 10m90’s now on both power supply boards and both Carbon amp boards are from the same batch from the same Chinese vendor...

Edited February 14, 2018 by bui501

[Whitigir]

I do not believe Chinese vendors, and did you test these parts before stuffing it Bui ?  Anything from Mousee is better.  I understand getting parts from the states would be harder than from China for Thailand , but I do not trust Chinese vendors 

Edited February 14, 2018 by Whitigir

[joehpj]

Buying from Chinese needs some more knowledge to know if the parts are genuine. I've bought from Taobao of 50 10M90S. Looked fine but turned out all fake.

If you know which vender to buy from, of course you can save a lot of money.

[JimL]

4 minutes ago, joehpj said:

Buying from Chinese needs some more knowledge to know if the parts are genuine. I've bought from Taobao of 50 10M90S. Looked fine but turned out all fake.

If you know which vender to buy from, of course you can save a lot of money.

Not really.  If the parts are fake and you solder them in, what you save in money you lose in time with a broken circuit. And then, you have to spend more time and money removing the bad parts and buying and installing real parts. Not worth it IMHO.

[joehpj]

I buy insulation ceramic kits, screws, nuts, or something like that from Taobao to cut the cost. I usually buy some samples first before I buy a lot.

After I bought fake 10M90S, I've never bought high voltage silicons from China. It's indeed better not to buy form China when building high voltage amps.

IMHO, it was like gambling. When you hit the jackpot, it explodes. LOL

[Laowei]

I’d sooner buy choudofu from a street vendor than electronic parts from Taobao or Alibaba. 

[Blueman2]

Bui501,

I did the exact same as you 2+ years ago.  I bought my 10M90S from eBay, China source I think.  Look at my thread "Exploding Zeners" below.

I am still not sure what exactly was going on with my 10M90s 'popping' but once I went with all Mouser, no more problems.     

 

Edited February 14, 2018 by Blueman2

[bui501]

That sounds like what happened to me on the positive rail board a couple of days ago: I thought it was just the thermal paste shorting the 10m90s to the heat sink.  I didn’t even make the connection til you referenced your earlier experience.

Ive got the 10m90s replacements on order from mouser now.

7 hours ago, Whitigir said:

I do not believe Chinese vendors, and did you test these parts before stuffing it Bui ?  Anything from Mousee is better.  I understand getting parts from the states would be harder than from China for Thailand , but I do not trust Chinese vendors 

Ah... but you mistakened me for someone more patient and wiser...  I was the idiot that fired up his brand newly stuffed Carbon build (amp boards and all) without proper heat sinking. It was what started my headaches in the first place. You’d think I’d learn a little patience from that, but I went with the Chinese vendor because it would save me several weeks of waiting for parts from mouser... so of course, I didn’t test the parts from China before excitedly soldering them in before the delivery guy even left my building. 

6 hours ago, Laowei said:

I’d sooner buy choudofu from a street vendor than electronic parts from Taobao or Alibaba. 

[mwl168]

10 hours ago, Laowei said:

I’d sooner buy choudofu from a street vendor than electronic parts from Taobao or Alibaba. 

Street vendors usually offer the best taesting choudofu. Easy choice !

[Laowei]

On 2/14/2018 at 8:04 PM, mwl168 said:

Street vendors usually offer the best taesting choudofu. Easy choice !

Depends on where you try it. Are you feeling lucky today? 

Had choudofu in Benxi years ago on a dare. Benxi in North China is a 2nd Tier city and few foreigners are seen there. Had LOTS of gaping mouth stares, chuckles and finger pointing by the locals at the laowei sitting on the curb and slopping up the smelly dish. At our western breakfast buffet the next morning, the girl that dared me to eat the stinky tofu would not try bleu cheese. 

In Guangzhou there are common official reports of choudofu being made skipping the long fermenting process by being marinated in human feces to get that stinky smell. Bon appetite! 

[mwl168]

Good point. 

I was referring to street vendors in Taiwan. Not surprised by what you said based on things I read and heard.

[Laowei]

1 hour ago, mwl168 said:

Good point. 

I was referring to street vendors in Taiwan. Not surprised by what you said based on things I read and heard.

Really wish to visit Taiwan one day.  Beautiful culture, beautiful scenery and beautiful people. 

[joehpj]

As a Taiwanese, I don't eat choudofu. I just can't stand that smell.

Laowei, please let me know when you visit Taiwan. 

[guzziguy]

I was introduced to "stinky tofu" in the US by a Taiwanese co-worker.  Hate the smell but love the taste.

[Kung]

On ‎2018‎年‎2‎月‎10‎日 at 10:09 AM, bui501 said:

A stack of 20 ea. CREE C2M1000170 SiC’s newly arrived directly from China... you’d think they’d be cheaper from China, but alas, no.



I’m just happy to be able to (hopefully) finish my boards this weekend.


In case anybody wants to order from the Chinese vendor, this is a link to them on Alibaba. You have to start a request for quote with them to get started. I paid $5/piece plus $20 for fed ex International shipping within Asia:

https://m.alibaba.com/product/60636916771/C2M1000170D-C2M1000170-TO-247-4-9A.html?s=p&spm=a2706.7843299.1998817009.1.r8CLBF


(On a side note, I had originally ordered from Newark.com when they claimed to have some in stock, but they never shipped my order and ended up refunding my money after weeks of delays. I won’t be using newark again.)



Sent from my iPhone using Tapatalk

it looks like fake c2m1000170 in the picture，but ones in the alibaba link below is real

 

[Laowei]

Yes, the ones in the photo are probably fake . 

This is one of my stash bought around a year ago from Mouser. Notice the stepped face the p/n is printed on.

[bui501]

2 hours ago, Laowei said:

Yes, the ones in the photo are probably fake . 

This is one of my stash bought around a year ago from Mouser. Notice the stepped face the p/n is printed on.

Damn!! Thank you, Laowei & Kung. 

I’ve  adjusted my original post so nobody else orders from the same vendor. The link is where I purchased from.  The photo I posted  was of what I received from them.

 

so does anybody have some spare CREE SiCs they can resell to me?

Edited February 18, 2018 by bui501

[chinsettawong]

Hi Vinh,

I have some of those.  Let me know how many you need.

Wachara C.

 

[bui501]

1 hour ago, chinsettawong said:

Hi Vinh,

I have some of those.  Let me know how many you need.

Wachara C.

 

Thank you, Wachara. Good to talk to you over the phone this afternoon.

Edited February 18, 2018 by bui501

[bui501]

And we have music!  After a 5-month saga of locating discontinued parts, melted SiCs, and counterfeit parts from questionable vendors, my Carbon boards with GRHV power supply is up and running!!!

Big THANKS and shout-out to the other members here, especially Sorenb and Blueman2 for identifying the cause of my original disaster (not properly heatsinking the SiCs and 10M90s) and the cause of the follow-up failures (counterfeit SiCs and 10M90s from China).  I wouldn't have known where to begin to troubleshoot let alone recognize the counterfeit parts.

Special thanks to Chinsettawong for lending me authentic replacement parts to complete my boards.  ?

In summary, two lessons I learned and am passing on for future builders:

1.  Proper heatsinking is absolutely necessary for the Carbon and GRHV -- not just for long-term use, but even just for powering up to adjust the current.

2.  Buy electronics parts only from reputable vendors -- and Yes, they do sell counterfeit MOSFETs in China that will blow up when powered up.

I'm so happy!!!  Now I just have to complete the front case and wiring.

[Blueman2]

Yeah!!!!  Congratulations!  Great news.  Yes, buying parts from a reputable source (Mouser or Digikey here in the US) is a hard learned lesson for many of us.  The other lesson I have learned is minimalism in amount of solder.  My Carbon went south about a month after build, but with sorenb's help I found I needed to remove excess solder and recheck all the joints.  No issues since. 

But I am really happy you got your baby up and running.  For case, I recommend one with big external heat sinks.  The carbon really puts out the heat.  

Well done, bui501!

 

 

Edited February 23, 2018 by Blueman2

[Pars]

Congrats bui501! And Blueman2 for getting yours running (and keeping it that way).

[chinsettawong]

Congratulations Bui501!  

[Whitigir]

Congrats! Finally   enjoy your Carbon 

[gnasherrr]

Hey guys. I'm somewhat new to diy and would like to ask some questions.

1. for the amp board. I was told to do the following modifications pictured below:

for the resistors circled in red use 75ks and for the green ones use 50ks

now I have close to 0 knowledge as far as circuits design goes, could someone tell me what they would change as a result?

2. I was told for the 450v version, the thermal might be a huge issue, also it might be pushing the limit of some of these parts in terms of voltage, currency or wattage ratings. Is any of this true? I want to ask because from what I read in the threads and it seems like people are having success on the 450v PSU.  Could someone clarify for me on that? 

 

I appreciate any time and effort in answering these questions in advance. Thanks.