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-   -   LM3886 fakes?? (http://www.diyaudio.com/forums/chip-amps/181792-lm3886-fakes.html)

norture 25th January 2011 01:03 AM

LM3886 fakes??
 
Someone in one of the LM3886 threads mentioned there ARE fakes of LM3886. Can anyone post an example or two? Because I think faking an IC is a big and hard thing to do so I doubt it..

linuxguru 25th January 2011 08:21 AM

Quote:

Originally Posted by norture (Post 2445175)
... I think faking an IC is a big and hard thing to do so I doubt it..

It may be hard to fabricate a counterfeit IC with the same specs as the original, but it's probably not that hard to take a lower-spec IC and re-package or re-mark it as a higher spec IC.

One could take a TDA series chipamp die like the TDA2050, add another die for the mute logic and package them together as a (fake) LM3886.

Alternatively, one could take an LM3876 and remark it as an LM3886 - even experts will be fooled.

Tarzan 25th January 2011 12:36 PM

I had a few (2) fake TDA1514 power chips.
The writing whas a bit different then from the original.
Allthough this is not the criteria for being a genuine or fake part.

Here is what happend:

After installation the chip lasted for about .1 second...
Used the second chip with current regulated power supply; draws excessive current on the negative side.
Bougth another from a reliable supplier in Germany; the unit works as supposed to be.
So I must conclude that your chips are fake.
I hope it's a one-off problem and not for all your chips. That would be bad, very bad.

The seller payed back the full amount of both chips.

If the price is cheap; take care...
Tarzan

jaycee 25th January 2011 06:52 PM

They also acquire factory rejects and sell them... or they sell an empty package, looks like the real thing, but has no die in it so it doesnt work at all.

Sadly eBay is the main outlet for these things - not worth the risk any more, too bad as that's where I got mine for a good price.

el156 25th January 2011 07:03 PM

There are lots of fake 2SA1301/2SC3280 in the market. The real ones cost 30 Euros an the fake cost 3 Euros......made in china.

db! 25th January 2011 08:21 PM

Here's one I got off ebay; the defects are glaringly obvious...

http://i281.photobucket.com/albums/k...g/DSCN0682.jpg
http://i281.photobucket.com/albums/k...g/DSCN0675.jpg

bichi 25th January 2011 09:01 PM

1 Attachment(s)
For comparison, LM3886 from National Semi samples program, circa 2008

db! 25th January 2011 09:28 PM

I have a hard time believing that those are real...

norture 26th January 2011 12:32 AM

Whoa! I never know that those are real fakes! Fortunately mine's look like the one posted by bichi.
It's a shame that they'd do business like this when we DIY'ers are just, well, doing our hobby and taking it for granted.

bichi 26th January 2011 02:08 AM

2 Attachment(s)
Two more possible clues:
- weight: 5grams (+/- 0.2grams) (uninsulated tab "T" version)
- appears the tab is copper with a tin/nickle/cad plating.

note:
- parts acquired 2007/2008.
- don't know if newer parts are "laser-imprinted," as opposed to "printed."


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