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Old 6th May 2011, 10:25 AM   #11
generg is offline generg  Germany
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Quote:
Originally Posted by CeeVee View Post
I also have quadruples from Spencer...genuine stuff, all measure as you say.

The 2SK170BL are not a problem it seems, i have plenty, all tested and matched.

It's the 2SJ74BL that are much more scarce that are the problem.
He delivers J74 too....
When I meant quadruples I meant two SK and two SJ, ideal for UGS!
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Old 6th May 2011, 03:23 PM   #12
masag1 is offline masag1  Germany
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Default pix of my 2SJ74BL fakes

I've bought mine from a Chinese supplier at DH Gate webside.

Range is from 3mA to 22mA.

Is there an easy testing methode?

Regards

Sam
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File Type: bmp Fakes miniatur ansicht.bmp (93.0 KB, 273 views)
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Old 6th May 2011, 05:57 PM   #13
heinz1 is offline heinz1  Europe
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Quote:
Originally Posted by masag1 View Post
I've bought mine from a Chinese supplier at DH Gate webside.

Range is from 3mA to 22mA.
....
Thanks for your image, masag1. The 2SJ74BLs bearing the code "7C" have already been described as fakes by @h_a here:

F5 power amplifier

Now you can guess that these "High Idss 2SJ74BL" offered here

20 X 2SJ74BL (10 Matched pairs) - HIGH IDSS | eBay

are also fakes (Seller says: They were manufactured in Malaysia)

Last edited by heinz1; 6th May 2011 at 06:03 PM.
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Old 6th May 2011, 06:13 PM   #14
heinz1 is offline heinz1  Europe
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Quote:
Originally Posted by CeeVee View Post
Yes Nelson there must be somewhere genuine parts but in past weeks i bought 2sj74BL from schuro, utsource and NIKKO and they all measure between 17ma and 20ma Idss......
....

Quote:
Originally Posted by PMA View Post
They would be most certainly fakes, I am afraid. I bought parts labeled as '2SJ74' from one HK supplier, as a trial. They also measured some 17 - 20 mA Idss. But have low transconductance AND noise higher about 20 - 30dB at low frequencies. I test the parts in my discrete preamps and noise spectrum + FFT distortion measurement are the best answer if the part is fake or not.

Regards,
@CeeVee and PMA:

What's the batch code of your fake 2SJ74s?
Thanks for the information!
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Old 6th May 2011, 06:39 PM   #15
PMA is offline PMA  Europe
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Mine was 'BL'. Obviously 20mA is a nonsense then.

The package marking seems to be overwritten. Those guys just took some P-JFETs and wrote '2SJ74BL' on them.
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Old 6th May 2011, 06:56 PM   #16
PMA is offline PMA  Europe
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I am attaching photos of genuine parts and fakes.
Attached Images
File Type: jpg genuine.JPG (37.3 KB, 854 views)
File Type: jpg fake1.JPG (28.5 KB, 835 views)
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Old 7th May 2011, 04:56 PM   #17
qusp is offline qusp  Australia
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and spencer is sold out now too
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Old 7th May 2011, 04:57 PM   #18
EBA is offline EBA  France
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Hi,

Selectronic dealer of france have all the time this parts in stock BL or GR kinds. You must just matched them.

This dealer have also other specific parts for audio : nichicon, elna, black gates capa ....

www.selectronic.fr
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Old 7th May 2011, 05:10 PM   #19
EUVL is offline EUVL  Europe
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Oh, I am sure Nelson still have tens of thousands, and Jacco thousands .....




Patrick
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Old 7th May 2011, 05:14 PM   #20
CeeVee is offline CeeVee  Portugal
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Quote:
Originally Posted by qusp View Post
and spencer is sold out now too
I got the last 20 pairs from him....
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