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if they came from eBay or equivalent and especially from China, very likely they’re fake
I would not call that fake, the difference is within typical fab spreads, let alone any official second source
The noise measuremnet would be interesting
Take a look at the top of TO92 package. Real Toshiba fets and bipolars have a 2mm wide line in center. If it is shorter line at the side, transistor is fake.
Brilliant, kamis!
Yes, the few genuine Toshiba 2SK170s I have, all have this thin raised line on top, in the centre, about 2mm long.
Whereas all the "suspect fake" ones I have ... have a line which is:
a. at the side - not in the centre, and
b. 1m long, max!
So I think this confirms they are fakes! 😡
Andy
I bought a brand new Marantz CD63SE player in the late 90's, it had been in storage till i recently brought it out to mod, while bypassing the HDAM circuit, i accidentally found 2 pairs of J74/K174 Jfets (V grade) in the circuit.
But the issue was they looked fakes, with straight 7 printings.
How can Marantz do that ? or are these really fakes ? Or are there another licensed OEM Jfets makers during the 90's ?
I m still confused !
Anyone doing this HDAM bypass mod please verify too.
But the issue was they looked fakes, with straight 7 printings.
How can Marantz do that ? or are these really fakes ? Or are there another licensed OEM Jfets makers during the 90's ?
I m still confused !
Anyone doing this HDAM bypass mod please verify too.
So what makes you think that a professional company the size of Marantz would not have a proper purchasing and incoming QC department ?
And why would they not purchase their components directly from the manufacturer or their official distributors ?
Cheers,
Patrick
And why would they not purchase their components directly from the manufacturer or their official distributors ?
Cheers,
Patrick
I totally agreed with you, that's why i m so puzzled by what i extracted out of their flagship cd player model in that era.
I believed CD67SE also have the same Jfets used in their HDAM circuits.
To get to the bottom of this, i encourage others whom are going to remove the HDAM in these CD players to take some pictures or video and share.
I believed CD67SE also have the same Jfets used in their HDAM circuits.
To get to the bottom of this, i encourage others whom are going to remove the HDAM in these CD players to take some pictures or video and share.
To get to the bottom of this, YOU can do the simple measurements suggested by PMA in #post 9.
Cheers,
Patrick
Cheers,
Patrick
And yet, Patrick, 'Stormsonic' in post 19 showed that measurements of fake units can actually be pretty close to genuine ones. 🙂
Andy
When i bought new then, my Marantz cd player sings well all those years, after which its laser suddenly can't read any disc and retired into my storeroom till recently...
I can do that for testing the Jfets taken out of the cd player, but that's not my point, i was hoping that someone with those Marantz flagship cd players in those era, to take a real look of what Jfets are in their set visually first, then idss and pinch test follows later.
Just to prove that whether they do came in with the straight 7 printing in another set or not.
I can do that for testing the Jfets taken out of the cd player, but that's not my point, i was hoping that someone with those Marantz flagship cd players in those era, to take a real look of what Jfets are in their set visually first, then idss and pinch test follows later.
Just to prove that whether they do came in with the straight 7 printing in another set or not.
> 'Stormsonic' in post 19 showed that measurements of fake units can actually be pretty close to genuine ones.
How does he know they are fake ?
Has he other meassurements such as noise, capacitance, ..... to prove so ?
Signing off,
Patrick
How does he know they are fake ?
Has he other meassurements such as noise, capacitance, ..... to prove so ?
Signing off,
Patrick
It is perfectly normal with the big manufacturers for the same die to be packaged and tested at several plants (often third party), often using different leadframes and moldings.
They are all genuine parts.
They are all genuine parts.
Not perfectly normal for the Toshiba 2SK170 which is the original body of this thread.
Give us your documentation that support Toshiba 2SK170 dies are assembled by a third party who intentionally use a smaller epoxy package from what was specified on the 2SK170 datasheet.
Has Toshiba told you that they only use one package style?
I don't believe that in the posts above that Marantz would have bought fakes and the HDAM module would not work with the typical die used by the fakers.
There are few third party test and package plants here in Malaysia, all producing finished parts for some of the semiconductor majors in a totally official and legit way. I am sure that there are others around SE Asia.
I don't believe that in the posts above that Marantz would have bought fakes and the HDAM module would not work with the typical die used by the fakers.
There are few third party test and package plants here in Malaysia, all producing finished parts for some of the semiconductor majors in a totally official and legit way. I am sure that there are others around SE Asia.
While I 100% believe the Marantz parts are genuine, it's been pretty well documented through measurements that many of the discontinued Toshiba jfets offered now are not genuine.
davidsrb,
Give me a Toshiba 2SK170 datasheet/ECN/ECO that supports your pure speculation of the existence of another 2SK170 TO-92 packaging dimensions that matches the OP's counterfeit 2SK170 measured dimensions. If you don't
have any just STOP!
You should be aware that reckless and unfounded statements just add more confusion to members which could end up as potential preys for counterfeiters.
That almost everything for sale now on auction sites is fake we are sure of, they don't even measure close
Even the Linear Systems LSK170 is being faked
So now that genuine thru-hole 2SK170s are no longer available - can anyone tell me the code for the SM equivalent?
Or the SM equivalent of the 2SK369?
Thanks,
Andy
Or the SM equivalent of the 2SK369?
Thanks,
Andy
Hi there,
if you are going to test a lot of transistors for fakes or otherwise, can I suggest you get yourself a Peak DCA 75 tester.
As well as testing the obvious parameters, it will plot the characteristics on a computer screen, which you can then chack directly against the manufactures' data sheet as a first level of confidence.
Brilliant investment for about £100.
Regards
Mike
if you are going to test a lot of transistors for fakes or otherwise, can I suggest you get yourself a Peak DCA 75 tester.
As well as testing the obvious parameters, it will plot the characteristics on a computer screen, which you can then chack directly against the manufactures' data sheet as a first level of confidence.
Brilliant investment for about £100.
Regards
Mike