Are these fake?

[glen65]

I just received some transistors from a place that I have
only ordered from once. Just need to know if either of these
new output transistors look like they may be counterfeit.
I purchased them from Audio Lab of GA.

Here are the originals.



These are the new ones.



Thanks.

[richie00boy]

Crack one open, then put a pic up. Right one looks real, left one possibly fake. In any case, the left one is from the lower gain band selection.

[Samuel Jayaraj]

I guess the one on the left is probably of Chinese origin. It will work but do not use it in an application which pushes the device close to its SOAR ratings. It might signal an early death knell.

[jaycee]

I agree with richie00boy, the left looks fake.

Audio Lab GA have already been caught selling fake Sankens, so it wouldn't be a big surprise if they're selling fake Toshiba's too.

See this thread:

http://www.diyaudio.com/forums/showt...812#post868812

[glen65]

I guess the one on the left is probably of Chinese origin. It will work but do not use it in an application which pushes the device close to its SOAR ratings. It might signal an early death knell.

Given their being used for output trannies I don’t think I'm going to risk it. It’s a good thing I only purchased the devices shown so I’m out about $11 bucks so it could have been worse. I think I will get some from someplace else. I might go with a replacement from On semiconductor that’s still an active device in order to reduce the chance of getting junk.

[anatech]

Hi Glen65,

I might go with a replacement from On semiconductor that’s still an active device in order to reduce the chance of getting junk.

That's an excellent idea.

-Chris

[MikeB]

Hmm, they look both like fakes to me...
Compare the cases to the attached ones. Very different !
(Mine are sourced from digikey)

Mike

[DCPreamp]

Hi There,

Check their BE capacitance against the originals. Legit devices should have similar capacitance suggesting the same size die and similar semiconductor topology. Fakes I've seen use smaller die and their junction capacitance is lower. Just a quick-and-dirty test without a curve tracer.

Paul

[anatech]

Hi Paul,
Yes. If you check earlier in this thread you should find some measured capacitance values and more pictures. It is a very long thread.

-Chris

[ifrythings]

I'd say there all fake, the ones MikeB posted look real. I always seem to see the fake ones with the wrong style of "o", they use either "O", "O with angled slash", but the originals from toshiba have the "O with slash down the middle".

The 2sc one isn't even from the same place as the 2sa, look at the small black area around the hole. I've even seen the hole not sentered with the black part(or green).

Just what I've seen latley.

BTW guru's, how do you open them?