LM308 - I smell a rat...

[chromesphere]

Somebody (sorry I cant remember who) reported a few weeks ago, 2 x lm308s I had sold them to be faulty. I had randomly tested about 5 of 20 of the chips, they worked so I assumed all good. I gave the buyer the benefit of the doubt and refunded the $.  Today I received 50 x lm308's for the webstore in the mail. 

On inspecting the tube the chips were all inserted randomly, facing up and down.  This worried me so I removed about 12 from one of the tubes.  The chips appeared to vary slightly from each other.  The indents were all over the place.  Some had pin 1 indents, some didn't.  They all had the large center - top indent but some were shallow and some were quite deep.  Also, about 5 had printed numbers on the underside and the rest didn't.  It looks like the chips have been mixed together from different batches and then inserted into the tubes at random.

So...I don't like selling stuff that doesn't work.  I would rather spend time to test and sell them at a higher cost, then sell them for less untested and hope they work.  After 2 hours of testing ( ) 8 of the 50 chips were faulty. Most of the faulty chips didn't pass signal, 1 sounded like it had a gain of about 2   the other motor boated.

I decided ok ill claim the 8 faulty chips through paypal.  Oh look at that....it appears I bought this lot through Polida....That name again!  But, I have bought these from a different seller and according to the customer mentioned at the start of this post, there were 2 faulty ones amongst those as well.

These are probably just faulty and not fake, but for those DIY'ing if your going to order 1 (on ebay) for a build, you might want to just go ahead and order 2...they are quite unreliable, and with a shelf life of probably (insert number here) years it could be expected I guess.

Your thoughts, opinions, experiences?

Paul

[marmaliser]

Are the fake / faulty ones from polida all the same looking ?

Photos of the fakes could be a help

[chromesphere]

No worries marmaliser.  I've decided to go to the trouble of using the good camera / tri pod to get a nice clear photo. 

Something interesting came up.  The 8 faulties / fakes are on their own in the bottom left corner.  I had noticed pen mark on 1 of the faulty chips (inside the large indent) when I was testing them.  I can see 1 and possibly 2 others that have pen mark in the over-exposure of the photo.  Coincidence or is this seller selling known dead chips!?

[marmaliser]

Thanks,  I'm leaning towards known dead than fakes. 
I have  few RAT's to build up so this is a timely reminder to test the chips first

I think it is proven now that Polida is just a tad on the Dark side !.  Remember how he used to ask people to cancel ebay orders after you received the chips !

[chromesphere]

Yeah, I don't think fakes are as prevalent as what the DIY community reports, most are probably just dead...as most likely are these 8 x lm308's.  But...selling KNOWN DEAD chips.  That's a whole new level....

[Govmnt_Lacky]

The fact that you have such a large quantity in the photos AND every one of them has the exact same batch number leads me to believe that they are fakes unfortunately 

[chromesphere]

Yep except they work and sound like an lm308.
or to say it another way these are the most awesome sounding fakes ive ever heard

[Govmnt_Lacky]

By fakes, I mean that they are NOT OEM parts. They are probably re-manufactured ICs using the same process but, not the same quality standards. I suppose that the proper term would be "counterfeit"

[Scruffie]

Polida re-stamps all their chips, real or not, simple as that.

You're better off looking at the bottom of the chips to see the variation.