Fake Toshiba 2sk2013/2SJ313?

[tamra]

I bought 2sk2013/2sj313 at yahoo auction just now but found some fake news here.

I saw seller's fet analysis but 2sk2013's Vgs-id looks weird.

2SK2013：Vgs = 1.782～1.970V Id = 5.00～5.05mA
2SJ313：　Vgs = 4.029～4.256V Id = 4.95～4.98mA

From datasheet,2sk2013's VHS must be around 2.5v.
And photo.
I might cancel my bid, could someone advice me if I am saying right or not?
Sorry for noob question.

 

[nattawa]

2SK2013 Vgs should be within a range 1.8V-2.8V see attached. This is not saying the device you ordered are genuine or not though. Good luck.

 

[prakit]

I have measured a lot of these FETs. For Id=40mA, most of K2013's Vgs will be around 2.1V-2.2V and J313's Vgs will be around -2.0 to-2.1V.
The pictures in the auction are too blurry to tell if they are fake or genuine. I have seen a lot of fake devices on Yahoo’s auction, sadly. Attached photo shows the genuine K2013/J313.
Hope this helps.

 

[tamra]

Thank you so much.

 

[Nelson Pass]

Toshiba's adherence to spec has always been so tight that I would be very suspicious of those numbers.

 

[G600]

tamra, I may be naïve, but as you are in Japan, there must be some old fashion shops with a few legit pieces for you?

 

[tamra]

Thank you so much for advice.
There is one shop sells unmatched 2sk2013/j313 in Tokyo.
I could buy like 20-30 each to make it closer.

 

[Nelson Pass]

Unlikely you need that many to get a decent match.

 

[tamra]

Thank you for advice Mr.Nelson.
I have not done matching fets yet so it might be fun.
I am planning to build Whammy headphone amp and Ba3 fe and more and more...

 

[tamra]

I would like to ask that how many pieces each for matching FQP3N30/FQP3P20 ?
I will use it for HPA1 clone.

 

[Nikos]

Here is mine .....from member Project16 fom France before 3_4 years .Since then I haven't heard from him again, I hope he is well and healthy...a very kind person.Based on this, i make my very good amplifier USSA 5 from Fab.

 

[tamra]

Thanks for clear picture.
I will go local shop and check the lettering.

 

[Drbulj]

https://www.diyaudio.com/community/...ttle-fb-160watt-amplifier.412261/post-7675832

Hi, check this post above, I bought these and were most definetly fakes. They have all lettering the same as yours, how possible is that 😂.
Skip them, and all unobtaniums, good circuits can be made with avaliable material

 

[tamra]

I have got refunded for the fakes.
The I found much trustable shop selling so I will check it out.

 

[tamra]

I bought k2013/j313 today.
It looks ok this time.
Now I have to study how to match them.

 

[tamra]

I am trying to measure using xrk971 easy peasy mosfet matching.
https://www.diyaudio.com/community/threads/nelson-pass-easy-peasy-mosfet-vgs-measurement.299546/
+15v R1=2.2k

K2013 shows 1.995v
J313 shows 1.861v
Is it right voltage?

 

[nattawa]

Your measured voltages appear to suggest the devices are within spec. According to the datasheet the test condition should be Id = 10 mA for Vgs-off. Since you were doing it at about 6mA, the measured Vgs value tend to be towards the lower side of the specified range (1.8-2.8V). If you do it at around 10mA, by lowering the R1 value to about 1.3K, you can expect the measured Vgs to go slightly towards the middle of the range.

 

[tamra]

Thank you.
I set R1 560ohm 20mA,
Vgs was 2.147v.
I will go with 10A.

 

[nattawa]

2.147V @20mA, you are most likely having what member "prakit" had as he described in post #3.