Fakes

[mirosol]

I sent the refund request (with the same evidence presented above) around 21:15 last night. The refund had come before four in the morning. Possibly the quickest refund i've ever seen. And i do think that is, at least to some degree, an admission of guilt..

Hoping to hear back from TI.
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[mirosol]

Just got an email from TI. They say that the markings match their production but they can't say if it's counterfeit or not. The main message is "we are not able to tell you whether this part is counterfeit, we can only ensure that when you purchase one of the official distributors in our parts. "

I hoped the message would have a bit more definitive. This just shows that TI isn't interested and you should not buy TI chips from anywhere else but from their official distributors. In my opinion, that's not very good stance to take. Basically they are just saying "Your bad, don't buy from quacks". I would have thought they would have some interest is weeding shit like that out...

That's pretty much it. All i can do is try to let as many people as possible to know that the eBay seller G&C is selling shit and everyone should avoid this seller. Better yet, let all their friends know this too.

So. Please, do not try to save a penny and get yours through ebay. Use Tayda, Banzai, Musikding, Mouser, Electron Electronics UK, or any other electronics shop that can be trusted. Sure, one can get refunds through ebay buyer's protection plan, but that doesn't help you much when you have a pedal sent to a friend 400 kilometres away with a counterfeit chip in it. Just shipping the pedal back and forth cost me about ten times what i paid for those ten bad LF347s. And how i missed the chip here on my desk? Well. The "ghost distortion" noise appears more vividly on low gain settings of the Boneyard circuit. I simply checked that the pedal was working with all the knobs maxed. Deemed it working and sent it away. Thankfully this was my only shipped pedal with a chip sourced from G&C .

My appeal to the chinese - Please, stop counterfeiting electronic components.
And while we're at it, Please stop counterfeiting anything.
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[Frank_NH]

Thanks for all your work on this Mirosol.  I've purchased many ICs on eBay and most all have been fine (I did get a bum CD4049UBE).  However, after my OCD squeal was fixed by changing the IC, it makes me think that perhaps there are a lot of op amps out there which may be good for non-audio applications but not good for stompboxes and related equipment, and so we need to audition several ICs (from different vendors) as part of the testing process.  This may help resolve some of those problems we see in circuits that we know are correctly built but they don't sound right.  

It makes some sense to me that a seller may come across a stash of, let's say, TL072s that may have been part of some repairman's collection for a few decades.  These chips then are sold without any testing being done, and so it's the purchaser's responsibility to see if it works and if not pursue a refund.  That's not ideal, and I think Mirosol has the right idea - only purchase from vendors you trust.

Here's a question I'll throw out to the group.  Can you construct an op amp tester for single and/or dual 8 pin op amps?  It might be a simple matter of constructing a simple non-inverting amplifier circuit and seeing if the output voltage gain makes sense.  Of course, this says nothing about AC signals, and you'd probably need an oscilloscope to know if there was a defect.

[rocket88]

I think that's a great idea, and something that might be good to tag it so we have an ongoing readource for reliable sellers, what to look for or look out for, and such. My I would think the best thing to do is have a circuit that you know works with a specific IC, drop in thw one for testing and play through it. I'm thinking that's the best way, since you point out that it could be some will work in non-audio applications, but we put them in a pedal and they oscillate. Idk, just my 2cents.

[mirosol]

I've never ran into issues with chips i've bought from Tayda/Banzai/Musikding/Mouser/Partco/Electron etc. Simplest way to test them is to build any simple boost/OD circuit and listen. For all genuine TI chips, the markings are clear and the recessed part is smooth. They look like quality items. For the counterfeits, not so much..

I too had a batch of non-working CD4069U** chips in the past. I bet those would have worked right as hex inverters for burglary alarms, but not for overdrives.. The first one that hits you always seems just like a bad batch. One can't think of foul play until it really hits.

I'm still rather sad about TI's answer. Anyway. For all of you, stick with decent sellers you trust. Even if you need to pay more. As cases like this show, it is definitely worth it.
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[jaredcohen]

When I used to work in computers I was told most of the RAM in the world is made in a handful of factories.  So if someone wants to go online and buy some cheap RAM from Patriot or Kingston, it's just RAM made by the big companies that was so out-of-spec they could never sell it at their prices... so they take pennies on the dollar and dump the garbage RAM on 3rd parties instead of throwing it away.  For many purposes the RAM is usable, so it's a good solution.

I'd wager that's what these "fake" transistors and ICs are... They may in fact be made by TI, or Fairchild, etc, and for the last 50 years when they have horrible out of spec batches, they've probably been dumping them in Asia and other developing markets.  They get to sell parts and make a few bucks instead of throwing them away, and they wouldn't tarnish their brand in the West, and the parts may be good enough for many purposes.  But now there's this whole global economy thing, and we go on eBay and buy those very same parts back.

But, I have no idea either.  That's just my hunch.

[mirosol]

That could be one explanation. But i doubt it, since the chips vary that much in visual aspects.
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