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Old 19th January 2013, 03:39 PM   #21
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There are good companies that make good transistors in China too! One of them is ISC (Inchange Semiconductors). If it is Chinese it does not necessarily mean that it is bad. Chinese produce all qualities from the lowest to the highest. Problem is how to know which one is good.
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Old 19th January 2013, 06:06 PM   #22
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Originally Posted by Bigun View Post
The best options in my view are:

- don't buy from China, at all.
- don't buy from individuals in general unless the parts are recovered from brand name amps
- some retailers do spend some effort to avoid selling faces, I use DigiKey in U.S.
- avoid using 'boutique' parts, they are the most tempting for fakers
- use vacuum tubes
No problem buying from China.
The worst example of counterfeit transistors I ever got, vas from the US.
I buy individuals all the time. Actually I have bought transistors from Farnell, and similar from China, and got better results when checking their properties than the oones from Farnell. Not everytime, but quite often.
Vacuum tubes are extremely hard to get into my transistor-projects.
By some strange reason they never seems to fit properly on the PCB.
And try to find a place to mount a screw in them, ti attach them to the heatsink.
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Old 19th January 2013, 06:21 PM   #23
Bigun is offline Bigun  Canada
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I agree, there are state of the art semiconductor foundries in China, and many other places nearby, that produce authentic parts. It's not my intent to imply they all make fakes or that all fakes are make in China. That would be biggoted to say the least. This issue, in my mind, is that the source of most fakes is from China. Before China there were few fakes on the market. There have always been clones, the Russians cloned many parts from the West (including vacuum tubes) and did a very good job, sometimes better. I feel very comfortable using Russian parts. But I do have the perception that the faking of parts is an issue that has been 'championed' by a minority of people in China. It's not a slight on the people of China as a whole, just my perception that most of the poor quality fakes originated there. It isn't just electronic components, it's everything - golf clubs, ipods, you name it. In my view, the ebay sellers in China are to be avoided as a first line of defence to buying fakes. Yes, there are unscrupulous vendors in other countries now too, unfortunately.

p.s. if you need to mount your vacuum tube to the heatsink, just drill a hole through it
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Last edited by Bigun; 19th January 2013 at 06:24 PM.
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Old 19th January 2013, 06:50 PM   #24
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The problem arose when the semiconductors of the sixties and seventies became scarce to find. This due to enthusiasts looking back to theese years, at the same time as the electronic companies just got rid of their "old" components opposed to their willingness to be there for their customers and supply customers with spareparts far beyound expected servicetime. Budget cuts and the demand to be more economical efficient made it impossible to take care of theese obsolete components.
And then the counterfeit-producers got their chance to cut into the market.
Russians, under tha ironcarpet was interrested in getting the very best, and as you say: Even make their copies better than the originals. A very different situation opposed to what the Chineese are in to.
And here we say chineese because they are the ones who are in the leading edge in this market now. Lots and lots of factories who compete for the BIG contracts, and when loosing those, they are forced to find other ways to earn money.

AH. Drilling holer in the tubes.
Well, no wonder I preffer semiconductors. They come with the hole finished.
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Old 19th January 2013, 09:47 PM   #25
ilimzn is offline ilimzn  Croatia
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Fakes come from various places on the planet, the same ones where the outsourced foundries are. One notable exception is China as there is an abundance of recycled parts from there, courtesy of most of the 'western world' selling them their e-trash to avoid costs of managing it's proper disposal.
It should be clearly noted that there are fakes and 'fakes' and 'second source components'.
Fakes are basic rubish that isn't usable in any sense, it's only purpose is to pass a basic test to convince the buyer it's really the component they want that they are buying. These can contain anything from literally nothing to sub-par silicon (say to fool a simple transistor tester), to a recycled untested or failed part (parts that pass normal tests are sold as genuine so more money to be made), to a reject from the actual foundry. Many unscrupulous individuals make a lot of money exploiting the lax laws in these countries making it possible to place rejected parts on the market rather than these being destroyed. There is an overabundance of this sort of thing in the IC market.
Then there are the 'fakes', or, euphemistically called 'compatible parts' which offer at least some semblance of the original, but are usually an older, simpler and cheaper to manufacture silicon die 'boxed' as a more expensive part. These are uaually sold for a lower price and in fact normally are not made to look like the original, although they may carry the same name (i.e. 2SC2922 but the other markings do not correspond to the original manufacturer, neither is it branded as such). There are tons of such 'brands', mostly out of China and India. Although they 'might' be usefull for something, beware - often these same people make the aforementioned fakes, and you can get really strange stuff such as a complementary pair where one transistor shows as a genuine (or close enough) part on a curve tracer, but the other is clearly a fake.
Finally there are the 'second source parts', one already mentioned manufacturer is ISC, but there are other better known such as Semelab. There are a number of manufacturers that specialise in 'twilight technology', replacements for older type parts, usually made using the same or close enough (often even slightly better tuned) technology. The problem with these is they sell bare dies to other people who can then pot them as whatever they like and it all becomes a lot of confusion because a manufacturer you never heard of may well do a real equivalent for your hard to find part but may be dismissed as a fake, while at the same time another more greedy one will pack a real but inferior spec die as a higher spec part to get a better profit.
For this reason there is really only one sure way to know, and that's a hammer and a microscope most of the 'fake' and 'second source' parts cannot be identified simply. Not even with a curve tracer (although that easily dispenses with outright fakes and some of the 'fakes').

One thing that should be noted is that the field of audio semiconductors is a somewhat special one. Basically all the audio semis we use today are based or literally re-packaged parts created in some cases as far back as 30 years ago. Practically all audio BJTs, and MOSFETs are at least based on devices developed in the late 70s, that have reached maturity in the late 80s. The rest up to now are really tweaks more than any great advances. Although most manufacturers do offer parts that are near-enough drop-ins for the old types, the prices are actually comparatively high and this is not helping the counterfeit problem. Most will argue that counterfeits make the prices high because they take a piece of the market reducing the demand to the manufacturer so that economy of scale dictates a higher price. But this very argument can be put upside down, because iff the demand was so low, then there would really be no market for cheap counterfeits either, because the profit in making them would be too low for anyone to actually make them. Demand for old devices from enthusiasts is not a big driving factor IMHO although some manufacturers have started to listen better, one notable example is ST, which is almost unique in manufacturing triple diffused transistors in a TO-3 case (again), which cover the demand for replacements for many types of Japanese TO-3 devices with Ft up to 20MHz (when they got to about 30MHz reliable plastic cases were already well in use).
In some cases the availability of parts is abysmal - small signal JFETs (not to metion larger FETs and VFETs...) have dwindled down to nothing. Sadly, the reason is simple - audio has long ago become a mass product, with very low prices - this segment of the market generates profit. People don't care too much about quality simply because they do not know what it is. 30-25 years ago this was cutting edge technology and luxury items, with profit generated by high prices (taking into account various other geopolitical and sociological situations of the time) but these then had to be justified with high quality. And - it was a time where hype did not work nearly as good as today. There ia big gap between consumer and 'high end' audio and to add to that, high end audio is full of superstitions - and the counterfeiters are nicely capitalizing on all this.
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Old 20th January 2013, 02:21 AM   #26
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Great, thanks ilimzn for another comprehensive and obviously well-informed post.

It is difficult for small-time DIY guys to understand the events behind their winding up with a few fake power transistors and manufacturers discussing global market issues about millions of parts, e-waste disposal and inferior product but they are related to profits, after all.
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Old 20th January 2013, 08:07 AM   #27
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Thank you ilimzn for the information, very helpful
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Old 20th January 2013, 11:40 AM   #28
ilimzn is offline ilimzn  Croatia
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Originally Posted by Ian Finch View Post
Great, thanks ilimzn for another comprehensive and obviously well-informed post.

It is difficult for small-time DIY guys to understand the events behind their winding up with a few fake power transistors and manufacturers discussing global market issues about millions of parts, e-waste disposal and inferior product but they are related to profits, after all.
Yes... I am sorry if my post looks 'over-done' but unfortunately that is how things seem to go. Sometimes it has very odd repercussions.

One example is the deluge of fake STK output chips. About 2 years ago I had a problem with this and ended up at one of the local distributor's warehouses, because I luckily knew one of the owners. It turned out that their entire stock was fake and in fact easy to identify as every single hybrid had the same serial number engraved into it.
The bigger surprise is what we found inside the hybrid (again, the hammer method was used). In actual fact it's a really well made surface-mount version of the part even using real output transistor dies on copper slugs - all genuine parts, EXCEPT there was no Vbe multiplier, and I mean not that the parts were not fitted, it was simply thrown out of the circuit and replaced with a short. The reason: it requires adjustment/trimming which the manufacturing machines can't do automatically.
This is an infuriating example of using real parts to produce trash, when $0.1 more would get you the real thing, possibly even better then the original, and able to fetch a good price on the market. I don't even know in what category I'd put this example, as it's basically wasting resources by destroying genuine parts out of greed and negligence.

The other side of the recycling story is that sometimes, with a lot of work and luck, you CAN get real 'unobtainium' parts. I won't quote an example here but by who knows what strange paths, some parts that were deemed never to have gotten from the prototype sample to manufacturing stage actually found their way into the stock of some obscure Chinese semiconductor dealers.
One other case I had recently were recycled 2SK181/182 SITs, extremely difficult to find in any case - these were obvious pulls, cleaned, with the surface re-finished and leads re-tinned. They test perfect too.

Re identifying fakes - the foremost consideration is to know if/when parts have been discontinued and what part has been introduced instead. Current production parts do ge faked but less likely than out-of production ones, which are fakes in the grand majority of cases.
Second: HAVE A GENUINE PART AVAILABLE if at al lpossible, for comparison, and by that I mean mechanical and electrical. Having a photo of the innards also helps.
Third, download original datasheets and study the original markings and codes on the case. In many cases the fakers try to circumvent the law (in case they do get tracked down), ditto 'fakes' and second sources, by not marking the parts the same as the originals hence 'everyone could see they are not original and buyer beware applies'.
Fourth, look carefully for any unique characteristic of a part. One good example are lateral MOSFETs. They have an unusual pinout, and low treshold voltage which is easy to test with a diode-test equipped multimeter. Mechanical clues are also informative, plastic mold sizes, tab size and thickness, weight.
Fifth - if you can't deduce by the above if the part is genuine, there is no other way but using a curve tracer, or - a far more common tool, a hammer. Unfortunately this is a problem if you buy on-line as you can't simply buy one part to sacrifice it to the hammer, then if satisfied about it's genuineness buy more, as you may get different parts the next time around. This sort of thing however works great if you are buying from a shop (say a spare parts supplier) - here it's not so uncommon to see people smashing just bought transistors on the curb in front of the shop itself (yes, it's come to that ). With on-line orders ask for a return policy, and if the parts are fake, you can use the smashed one as proof, offer to the supplier to not ask for a return for that one.

And then... there are the fake capacitors and elecrolytics and even resistors...
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Old 20th January 2013, 11:50 AM   #29
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One day some Pirate will realise that he could make some REAL money by manufacturing rare obsolete electronic components. Not fakes but bonafide pattern copies.

Oh - I'm dreaming again.

Car manufacturers have sold on the tooling dies for body parts for many years.
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Old 20th January 2013, 04:53 PM   #30
HighTec is offline HighTec  Croatia
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here it's not so uncommon to see people smashing just bought transistors on the curb in front of the shop itself (yes, it's come to that ). (
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