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Pairing of store jfet DIYAUDIO
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Old 24th April 2019, 08:13 PM   #11
Dennis Hui is offline Dennis Hui  Canada
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Pairing of store jfet DIYAUDIO
Hi uchu007, for Idss, you probably want to test with Vds=10V and Vgs=0.
Your tester seems to be quoting Idss values at varying and quite
low Vds voltages.
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Old 24th April 2019, 08:23 PM   #12
uchu007 is offline uchu007  France
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Quote:
Originally Posted by Dennis Hui View Post
Hi uchu007, for Idss, you probably want to test with Vds=10V and Vgs=0.
Your tester seems to be quoting Idss values at varying and quite
low Vds voltages.
Yet the idss of the peers that I had from Punkydawgs are well 7.35 for the 2sk170 and 7.38 for the 2sj74 and those of the store that I just received are much lower below 6ma
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Old 24th April 2019, 10:29 PM   #13
Zen Mod is offline Zen Mod  Serbia
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Pairing of store jfet DIYAUDIO
as I said - test them at higher voltage

besides that , that guy above ( better known as My Papa), claiming 1mA as OK , is a guy who made that amp

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Old 24th April 2019, 11:51 PM   #14
Dennis Hui is offline Dennis Hui  Canada
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Pairing of store jfet DIYAUDIO
For the B grade, the Idss should be between 6 and 12 mA, and
is based on current value with Vgs=0 and Vds=10.

When I look at the 2sk170 Vgs=0 blue curve near the top of the graph in your first post
and extrapolate to Vds=10, it looks possible the curve will make it over 6mA.
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Old 25th April 2019, 12:09 AM   #15
uchu007 is offline uchu007  France
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I still think that I will use the pair that I got on ebay in Punkydawgs and that those from the store will stay in their box!Because I’m pretty thorough and it’s really going to bother me to have such a gap. I still have the memory that in the French magazine Jean Hiraga explained that it was necessary a very demanding pairing of transistors and that it was important
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Old 25th April 2019, 12:18 AM   #16
Zen Mod is offline Zen Mod  Serbia
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Pairing of store jfet DIYAUDIO
different amps , different criteria
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Old 25th April 2019, 12:40 AM   #17
uchu007 is offline uchu007  France
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Ok Zen mod in any case I thank you all and especially Nelson for these sharing! I enclose a small photo of the assembly of the cards in progress ......
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File Type: jpg IMG_20190425_013557.jpg (725.9 KB, 201 views)
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Old 25th April 2019, 01:01 AM   #18
Dennis Hui is offline Dennis Hui  Canada
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Pairing of store jfet DIYAUDIO
As Papa has said, this is the entertainment business, so use the parts you
want to give you maximum enjoyment and not keep you up at night.

Have fun with your build!

Dennis
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Old 25th April 2019, 03:42 AM   #19
Jason is offline Jason  Australia
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Pairing of store jfet DIYAUDIO
Hi Uchu! The store is only interested in your total satisfaction.

You have now heard what is required for your project. As Dennis said you should absolutely use the parts that give you maximum enjoyment and let you sleep well at night.

However in this case it does look like some more testing needs to be done. Mistakes can happen and if these are actually outside of the standard we'll of course make things right. Please get in touch at contact@diyaudiostore.com so we can take care of you.
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Old 25th April 2019, 10:48 AM   #20
uchu007 is offline uchu007  France
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Quote:
Originally Posted by Jason View Post
Hi Uchu! The store is only interested in your total satisfaction.

You have now heard what is required for your project. As Dennis said you should absolutely use the parts that give you maximum enjoyment and let you sleep well at night.

However in this case it does look like some more testing needs to be done. Mistakes can happen and if these are actually outside of the standard we'll of course make things right. Please get in touch at contact@diyaudiostore.com so we can take care of you.
Hello Jason,
I already contacted you by email. I mounted the pair I had on the bay because the ones in the awning are not close enough for me.
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