Hi to all.
I may have a possibility to source some 2SJ109 (but few of them...not more than 2/4) V grade.
From some search on the forum i found that for the Aleph J (i plan to buid) preferably they must be BL type, GR won't work but not so much info about the V type.
I would say it should be ok but could you confirm me this and eventually modification from the original schematic from Mr PASS in case it's needed?
Many thanks to you.
Krivium.
I may have a possibility to source some 2SJ109 (but few of them...not more than 2/4) V grade.
From some search on the forum i found that for the Aleph J (i plan to buid) preferably they must be BL type, GR won't work but not so much info about the V type.
I would say it should be ok but could you confirm me this and eventually modification from the original schematic from Mr PASS in case it's needed?
Many thanks to you.
Krivium.
Hi,
the AlephJ biases the frontend with the aid of a constant current source at 8.3 mA; so regardless of grade anything works that has an IDSS of above 4.15 mA (the 8.3 mA is split between the 2x jfets in the package).
You can use it (without modifications), however, there might be better chances to use the V.
Hannes
the AlephJ biases the frontend with the aid of a constant current source at 8.3 mA; so regardless of grade anything works that has an IDSS of above 4.15 mA (the 8.3 mA is split between the 2x jfets in the package).
You can use it (without modifications), however, there might be better chances to use the V.
Hannes
Hannes thanks for the answer.
Bill could you explain more? EG for the 2SJ109V in Aleph J it would be a modification of R8 from 1k to 500r for example?
I generally use an Idss as high as the total front end current, which can be adjusted to match the Idss of the jfets you are using.
Bill could you explain more? EG for the 2SJ109V in Aleph J it would be a modification of R8 from 1k to 500r for example?
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