Hi Alex...sorry for my mistake....i also have ECW20N20 .
My idea is only for solve the problem of reperibility of SJEP and to use something better than IRFP.
feel free to try it
even with lower xconductance, that can be very nice amp
GenergeticFor me the sound with only one 2SJ109 BL was too soft. Two 2SJ109 BL or four SJ74BL made the sound more energetic.
Maybe I should try parallelling in my sloppy joe B1R2
We discussed OLG, and not distortion. Correct ?
I measured by curve tracing at 55°C Yfs of SJEP120R100 to be ~6S at 1.3A.
That is 0.17R intrinsic source resistance.
Add that to the actual (hardware) source resistor give you the totoal effective source resistance (SJEP + Rsource).
So you can now determine how much to gain by changing the value of Rsource.
It does not say anything about bias stability over temperature.
For that of course you need to contact experiments on heatsinks.
Spice is only as accurate as the model you use.
I always measure to cross check with simulations.
Cheers,
Patrick
I measured by curve tracing at 55°C Yfs of SJEP120R100 to be ~6S at 1.3A.
That is 0.17R intrinsic source resistance.
Add that to the actual (hardware) source resistor give you the totoal effective source resistance (SJEP + Rsource).
So you can now determine how much to gain by changing the value of Rsource.
It does not say anything about bias stability over temperature.
For that of course you need to contact experiments on heatsinks.
Spice is only as accurate as the model you use.
I always measure to cross check with simulations.
Cheers,
Patrick
I searched in my parts bin today and found a matched quad at 10.6ma of j74bl. I also found 2 quads of matched k117gr. One is at 4.3ma and the other at 5ma.
Should I go with these or it’s better to order the ones with the required idss?
Should I go with these or it’s better to order the ones with the required idss?
Attachments
I see a problem.... the four J74 are BL as in the original, but the k117, may not be good.
Either two 2SK170 or 2SK370 in parallel with an Idss adding to 10mA are requested.
Of course 5mA and 5mA would be the best solution, to share the current equally.
Either two 2SK170 or 2SK370 in parallel with an Idss adding to 10mA are requested.
Of course 5mA and 5mA would be the best solution, to share the current equally.
2SJ74 is P-JFET, 2SK117 is N-JFET.
2SK117 is the TO92 version of 2SK209.
Already published in 2018.
https://www.diyaudio.com/community/threads/njfets-for-source-follower-applications.329131/
Patrick
2SK117 is the TO92 version of 2SK209.
Already published in 2018.
https://www.diyaudio.com/community/threads/njfets-for-source-follower-applications.329131/
Patrick
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