### Counterfeit transistors

[Leolabs]

Just "ISC made" power transistors,not counterfeit "Sanken".Nothing to
worry about,just they can't be push hard,still usable for normal power applications.

[sbrook]

Originally posted by Eva
I wonder if we have some fake seller friends here trying to avoid the embarrasement...

Since I'm the only one here really suggesting that these could be quite usable transistors, this is clearly pointed at me.

Well, Eva, I am not in the components sales business. The smallest "component" you can buy from me right now is an Digital RA90 disk drive for about $50 or a PDP-11/83 CPU card for about the same because ancient computer spares is part of my computer consulting business.

Just so we're clear here. I *am* an electronics engineer and have been since the 1960s but got into computers as my business in 1976. Whilst I have considered selling components for hobbyists, I have no interest in getting into the sales of Japanese type (2S etc) semiconductors for the very reason that you are all experiencing with either low quality components or outright counterfeit useless components. What I would want to source are name brands of a standard range of N. American and European transistors. There's enough fakery in these but I would only buy production types.

So please be careful in tossing around comments like you did.

Thanks!

[small_boy]

They don't have a datasheet for a good reason... lol...

oh, ISCSemi produce the 2SC2922. But the homepage of ISC has many bugs. One is that there has a big hole in the Transistorlist in the html table between page 3 to 4. Lost one complete page with many transistor. And the other that you cant donwload datasheets for the 2SA. when you klick on pdf icon you come back to the same page. On all pdf icons by 2SA transis. For a big company is that a bad page *lol*

In the pdf download file, the 2SC2922 is in the list with following data:

ISC 2SC2922
Pc(W) : 200
Ic : 17
Vceo : 180
Vcbo : 180
Vebo : 5
Hfe by Vce(V)=4 Ic(A)=8 : 50-
Vce(sat) by Ic(A)=8 Ib(A)=0.8 max : 2
Ft(Mhz) : 50

Sanken 2SC2922
has the same data, when i look right, only the Hfe begins smaller by 30- and then higher.

Why manufacturing 2SC2922 and 2SA1216 under another name? Because Sanken parts are of great quality and widely used, and there will be always people willing to buy the same part number with another brand for less money and expecting them to be as good the originals...

I have the same problem, In the last day in known now that 4 company´s produce 2SA1216 and 2SC2922.

Frist :

Sanken : http://www.sanken-ele.co.jp/

and then :

ISCSemi : http://www.iscsemi.cn/
Mospec : http://www.mospec.com.tw/
WingShing : http://www.wingshing.com/en/

All produce this transistors in mt-200, only mospec produce it in top3.

but when you google about the other Company´s you dont find any infos about this and 2S transistors.

Has here any other infos about this companys and use one of the transistor from one of these companys ?

i hope that my 2SC are ok and hold what the datasheet says.

In future i will only buy original Sanken by a official distributors here in germany.

Knows everyone a official distributors for sanken in germany ?
Is Schuro a official distributors for sanken in germany ?

http://www.schuro.de/preisl-jap-trans.htm

Dirk

[Eva]

I stumble at MOSPEC parts from time to time and quality seems reasonable, at least I think that their manufacturing process is better than the white silicone stuff... If they weren't able to clone the MT-200, the TO-3P seems like the right choice because the heat spreader is thicker and more effective than the flat and thin one used in the fake MT-200.

The transistors from KEC that I have seen also seemed to be of good quality (at least their old TIP35C and TIP36C were very rugged) http://www.keccorp.com/

Korean companies seem to be far more honest than Chinese ones.


Please accept my apologies, sbrook. Fakes get me angry because I like to use the full capabilities of transistors and ICs. For example, once I built a quick amplifier prototype with +/-80V rails and two pairs of genuine 2SC3264/2SA1295 and it was able to drive 4 ohms without failing (was it the heavy copper heat spreader?). I can't agree with anybody stating that fake parts are useable, as there are plenty of genuine lower power parts capable of doing the same job, even for *less* money. By buying and accepting fakes you are giving profit to the wrong people and encouraging them to produce more and more fakes. We must stop this process by proving to component dealers that they can't successfully sell us anything but high quality stuff (so that they stop buying junk from obscure sources).

[Nordic]

I jsut want to say that I replaced suspected fake Toshiba 2sc5200 for ISC 5200 and complimentary, and the sound change was an improvement in my opinion. Also I have driven the amp to about its dynamic max for 12 hours over newyears...

Sadly many of us have to choose between the devils we know becasue of lacking distrubution setup of the main manufactures....

For the transistor I mentioned, I need to buy 100 at more than digikey single cost from the local authorised distributor...

[GKU]

Hi Dirk, Eva,

I agree, we should never accept fake parts and should without any excuse legally attack their sellers.

On the other hand, the devices in question are general purpose power devices. The audio market compared to general purpose application is very small. The Sanken have got a good reputation in the audio market, but still the main volume is produced for general purpose for which the audio quality - which by the way can not be measured - isn't relevant.
As I have mentioned in my previous post, any manufacturer who has been registered and accepted at JEDEC as manufacturer of such devices can produce it as long they are in line with the registered specifications.
In addition for audio power application the hfe variation spec is important. If the variation is much lager than from the original device, matching transitor pairs is unavoidable.
My personal experience with devices from second source manufacturer show larger hfe variation, which make them finally more expensive if you need to buy more and select acceptable pairs.
If people intent to use devices produced from other suppliers than from Sanken as it is here the case, must keep in mind that there can be some sound deviations as previously mentioned.
As long as the manufacturer don't use the Sanken trade name it is a normal and legal proceeding.
For audio application I would anyway recommend to use only the original proposed device type for which the circuit has been developed.

Dirk,
I have also checked the iscsemi product list and couldn't find the page with the 2SC2922. But I have send them an e-mail with my request for such a device. Let's wait for their answer.

At this moment I don't know any official Sanken Distributor in Germany, but I will find out over the Sanken sales department.
Schuro isn't an official distributor only a dealer. If Schuro propose original Sanken devices, according to German roules, Schuro will be made responsible for the origin of their products - again if "Japanese product" has been mentioned, Japanese must be in - in your case Sanken.

Cheers

Gerd

[small_boy]

Dirk,
I have also checked the iscsemi product list and couldn't find the page with the 2SC2922. But I have send them an e-mail with my request for such a device. Let's wait for their answer.

you find the 2SC2922 on a list, that you can donwload. Look on top in menu "Company->Download Center" and the download Datasheet.pdf In this list you find the lost 2SC transis.

Schuro isn't an official distributor only a dealer. If Schuro propose original Sanken devices, according to German roules, Schuro will be made responsible for the origin of their products - again if "Japanese product" has been mentioned, Japanese must be in - in your case Sanken.

thats the problem. Nobody know a official Distributor for Sanken. All know only normal dealers.

I wonder once what ISCSemi says. i dont get a answer after my second question and send them the picture of the dirty rag.

When the 2SC2922 is a original ISCSemi that hold the spec, thats ok for me (the ISC cost a half of Sanken) but when its not ok, its a fake of ISC or other and my Amps burn out, then i become a big neck.

But at begin next month i have birthday and then i will buy original Sanken !!!

But you have right. ISC are Chinese and not Japan, how it is in the list at reichelt!

Dirk

[sbrook]

Originally posted by Eva
Please accept my apologies, sbrook.

Thank you ... accepted.

[QUOTE[Fakes get me angry because I like to use the full capabilities of transistors and ICs. For example, once I built a quick amplifier prototype with +/-80V rails and two pairs of genuine 2SC3264/2SA1295 and it was able to drive 4 ohms without failing (was it the heavy copper heat spreader?). I can't agree with anybody stating that fake parts are useable, as there are plenty of genuine lower power parts capable of doing the same job, even for *less* money. By buying and accepting fakes you are giving profit to the wrong people and encouraging them to produce more and more fakes. We must stop this process by proving to component dealers that they can't successfully sell us anything but high quality stuff (so that they stop buying junk from obscure sources). [/B][/QUOTE]

I can understand what you're saying, but at the same time there are copies (made by other companies but cheaper) and there are fakes (made by rogue outfits and are not in any way what is being sold.

In most industries, copies of things are made "under license" because of copyright type issues. In the semiconductor industry, unless a part uses unique technical patented construction methods, licensing is often not needed, or they're made in places where licensing is not required. Many copies are made with subtly different parameters.

Fakes or counterfeits are a different matter altogether. They are intended to sell what appears to be a brand name product but is nothing of the sort ... not even close.

ISC do copies and not necessarily particularly good quality copies at that. If you buy a "copy" and know you're getting a copy (as opposed to a transistor made by the original manufacturer like in this case, Sanken) then you should be accepting the fact that you're not getting the top quality, but you should be getting something close.

It's kind of like the generic drug industry. There are companies that make patented drugs "under license" and there are those who make copies of out of patent protection drugs we call generics, both of which are copies.

I take a medication that is quite inexpensive as a generic, but about 1/3 to 1/2 the cost of the original brand name manufacturer, and the generic works, but there are differences. The generic has a different release rate to the brand name and different release rate between batches. It works but the overall effectiveness of the medication is not as good as the brand name. BUT I can't afford the brand name because I don't have a drug plan, so I use the generics which provide me with adequate relief from my condition.

As was mentioned by someone else, if someone wanted to do fakes of these transistors, it would make no sense to do a fake of an ISC, nor would it make sense to put in 36 sq mm dies, when standard practice is to put in a small signal transistor die and label it with the brand name (Sanken).

So, my point is that these are probably copies and not fakes. It may be a reasonable, or it may be a poor copy - testing is the only way to know.

The question is what did the OP buy?

Did he think he was getting Sanken Japanese transistors? If so, then he was ripped off and should absolutely return them.

Did he know he was getting ISC transistors? If so, he probably got what he paid for, and the only way to make sure is to thouroughly test them. If they test out to a reasonable tolerance of the ISC part specs, then he's got what he ordered - maybe not what he was hoping for - but probably didn't realize the ISC copy was not going to be as good as the Sanken original. If on the other hand the test of these shows them to be outside tolerance of the specs of the device, then he should return them.

[Eva]

Of course, there are good copies and bad copies. For example, Fairchild is producing KSC5200 and KSA1943 with similar quality to Toshiba original parts.

The point is that MT-200 transistors by definition have a big copper thermal pad soldered on top of the back plate (see pictures) and any good copy must include this thermal pad because it's required to achieve rated power handling and SOA. The copies made by ISC don't include it, instead, the bare die is attached to a thin bottom plate resulting in TO-220-like power handling.

[TOINO]

Originally posted by GKU

At this moment I don't know any official Sanken Distributor in Germany, but I will find out over the Sanken sales department.

Actually Sanken is distributed by Allegro http://www.allegromicro.com/en/