Ok so maybe I was being stupid thinking that I could buy 5x MC12080 prescalers from China on eBay for £3.79.
If I order from mouser uk I would pay £3.99 each plus £12 delivery.
When I tested them, instead of dividing by 10,20,40 or 80 as determined by the S1,S2,S3 inputs, they divide by 2,4 or 8.
I suspect they are MC12093 devices.
A while ago I bought some LM4562 op amps from eBay. They turned out to have a GBW of about 4MHz instead of 55MHz.
I suspect they were really TL072 or similar.
I spent ages trying to figure out why my design did not work as expected.
I'm getting really fed up with being sold fake crap from China.
So I'm going to name and shame the sellers:-
'hia5' sells fake LM4562.
'gc_supermarket' sells fake MC12080.
AVOID!
Welcome to planet Earth, friend. Everything on auction sites is fake unless you have good reasons to believe otherwise.
(That being said, the fake LM4562 I have seen so far were NE5532, TL072 is disappointing.)
@op next time you need to buy a part, ask yourself a question :
- is my time wasted on troubleshooting worth £12 delivery.
Ok so maybe I was being stupid thinking that I could buy 5x MC12080 prescalers from China on eBay for £3.79.
Wait, you're actually surprised that you got fake stuff for the impossible price?
Oy.
What else to expect??? Don't buy anything of value from China on ebay, because it's 90% relabeled junk!
Made that mistake with power mosfets, got relabeled junk salvaged from scrap yard.
Same with GAL PLDs, everything with 24legs can be ground off and re-lasered as GAL20V8.
Some sandpaper and a laser, $0.20 LM358 becomes $2 LM4562. And it will hard to tell the difference, unless you do some testing.
Some sandpaper and a laser, $0.20 LM358 becomes $2 LM4562. And it will hard to tell the difference, unless you do some testing.
That's some expensive shit. More like $0.02 opamp becomes LM4562.
I have experienced the fake cr@p from China via eBay feeling of disappointment... but only a relatively small percentage of the time. Most of the time, the parts I get have been genuine.
I always check the "normal" distributors first - only if their prices are stupid (they aren't always) do I head for eBay.
Most of the time, the parts I get have been genuine.
Most likely you did not notice the difference in many cases. Not all parts are counterfeit but their amount and overall share is overwhelming.
I suspect that it's the "audiophool" and "hobbyist" parts which are faked the most, followed by obsolete parts which are likely to be recycled. Your chances are probably much better if you buy some obscure or specialized ICs that are still in production and pay reasonable price for them. OTOH for many beginners, particularly those shopping on price, fakes are virtually guaranteed.
Most of the time, the parts I get have been genuine.
Most likely you did not notice the difference in many cases. Not all parts are counterfeit but their amount and overall share is overwhelming.
If you are familiar with the part, you are probably not so easily fooled as with an unfamiliar part.
As a hobbyist, your trade-off is a lower price in return for a little testing... you can always get your money back if the item is fake.
The worst example I've seen was a bunch of NPN transistors rebadged as JFETs. They couldn't possibly work in any circuit designed for a jfet...
As a hobbyist, your trade-off is a lower price in return for a little testing...
Little testing does not expose the vast majority of counterfeits, only the most blatant. Often you receive salvaged from e-waste and remarked stuff sold as new, rebadged to sell as better grade and whatnot crap you can only imagine.
As a hobbyist, your trade-off is a lower price in return for a little testing...
Little testing does not expose the vast majority of counterfeits, only the most blatant. Often you receive salvaged from e-waste and remarked stuff sold as new, rebadged to sell as better grade and whatnot crap you can only imagine.
Fair enough, but if it works well enough to be acceptable by the hobbyist... it is like a placebo, makes the patient well?
The latest research says that a placebo works,
even if the patient knows it is a placebo! Personally, as long as the part tests well for my purposes, would I be OK with a recycled part with re-welded pins etc. in return for saving significant $$$? - Maybe.... It would of course be more honest of the seller to list such items as "Refurbished" rather than "New".
Fair enough, but if it works well enough to be acceptable by the hobbyist... it is like a placebo, makes the patient well?
The latest research says that a placebo works, even if the patient knows it is a placebo!
Exactly. The audiophile is happy because his new LM4562 sounds better than the TL072 it upgraded, the Chinese guys is happy because he made some money harvesting that TL072 from scrap PCBs and the environment is happy because the IC didn't end up in a landfill. Win win
Little testing does not expose the vast majority of counterfeits, only the most blatant. Often you receive salvaged from e-waste and remarked stuff sold as new, rebadged to sell as better grade and whatnot crap you can only imagine.
I would estimate 99% of IC's that end up in e-waste are completely functional. If they can be safely recovered, they will be fine.
Of course if they are remarked or advertised as new, that is an issue.
Personally, as long as the part tests well for my purposes, would I be OK with a recycled part with re-welded pins etc. in return for saving significant $$$? - Maybe.... It would of course be more honest of the seller to list such items as "Refurbished" rather than "New".
There are a few sellers that are honest like this but its not many on ebay I know of.
It can be worse. I bought
OPA627 for use in audio DACs, off eBay and Aliexpress. The IC's have very low distortion and work fine, although they will RF oscillate if you go near the offset trim pins, which I think strange. Non-vanilla op-amp prices are just obscene.
OP627 $25 Digikey
OP627 $4 eBay
AD744 $8 Digikey
AD744 $2 eBay
AD797 $11 Digikey
AD797 $3 eBay
Apparently one possibility with OPA627 knockoffs are some other Burr Brown part or AD744 according to
Zeptobars die shots. So I purchased legit AD744 but no RF oscillations at the offset pins, but they do have different sound, a different IC.
So I have no idea what IC's I've actually got
So I have no idea what IC's I've actually got
Test things like quiescent current, offset voltage, noise, input bias current (is it FET or BJT to begin with?), GBW (shows up as a knee on noise measurements at high gain), slew rate...
Even if you can't identify them, at least you will have some clue if they are any good.
What if they are real 627
They could be genuine, we have no idea where the silicon fab is done for these parts. Packaging, font etc. looks like the usual low grade though. I would expect them to be rejects, overruns or untrimmed.
USD $25 for a single op-amp, $50 for a stereo pair from Digikey, OUCH! $37 for DIP-8.
Fake audiophile opamps: OPA627 (AD744?!)
I don't bother at all with Ebay, Amazon etc for parts anymore. Digikey is cheap enough in general and at least I get genuine parts. Basically I feel the piece of mind is worth whatever extra it may cost compared to some deal on Ebay. I have some Amazon parts in my bins like resistors and capacitors but those you can go less wrong, if you don't care too much about specific ratings. (ex: non production stuff and just playing around) Typically that stuff is just to pad an order to get free shipping.
Quite boring reading this kinda whines everytimes ... a typical noob online shopper.
I would expect them to be rejects, overruns or untrimmed.
Everybody talks about "possible rejects", nobody has ever demonstrated evidence that it happens
IME fake opamps are either completely different parts which don't even come close to meeting the specs or obviously recycled (stains, scratches, shiny non-PbF lead finish, false markings or genuine markings and random date codes in a lot).
Where do you think the dies go that work but fail specs? Even in the 1970's they ended up packaged and sold, although widely known at the surplus houses. Nothing goes to waste in china.
I couldn't test all the specs of an op-amp, that's a lot of work. Russians are measuring pin capacitance as a test for counterfeit BJT's and IC's.
I usually encounter fake IC's that do absolutely nothing, as if there's no silicon inside.
Heh, I knew people who interned at an IC shop and took failed dice as souvenirs but they had to sign a declaration that they will never resell them to anyone. The rest was destroyed.
I suppose there is a chance of "leaks" and I don't know where they go, but most of the fakes on auction sites aren't them. If they exist, nobody has found and positively identified one so far, to the best of my knowledge.
Where do you think the dies go that work but fail specs? Even in the 1970's they ended up packaged and sold, although widely known at the surplus houses. Nothing goes to waste in china.
I couldn't test all the specs of an op-amp, that's a lot of work. Russians are measuring pin capacitance as a test for counterfeit BJT's and IC's.
I usually encounter fake IC's that do absolutely nothing, as if there's no silicon inside.
I guess the less than honest seller hopes you will put it straight into inventory and not discover the issue until enough time has passed that they cannot reasonably be blamed...