The right direction? 😕
value of source/drain resistors
LED positioning
emiter of opto bjt in wrong point
I'll say no more ......
no J2 Babelfish from Mighty ZM
transistor part - better , but resistor values still not good , same as termination of LED part
........ and - you have few missing parts
google for nelson pass , optical bias , patent
........ and - you have few missing parts
google for nelson pass , optical bias , patent
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I do not see any need for the optocoupler. Why not use a tl431 as Nelson does? maybe supply the tl431 by a CCS to ease its work? I even guess, thats not necessary, I would just put a 220uF cap across it to make it a stiff (whatever so adjusted) voltage offset...
The feedback connection would care for dc stability, and I guess, a 2SJ109 is preferable to single silicon devices...
But hopefully Nelson shares the secret, I have 2sJ109, semisouth ans 2sk170 waiting...
Dirk
The feedback connection would care for dc stability, and I guess, a 2SJ109 is preferable to single silicon devices...
But hopefully Nelson shares the secret, I have 2sJ109, semisouth ans 2sk170 waiting...
Dirk
ak4396 - would you like to share your spice model of that precious device (sjep..) or point me in a useful direction.
Well, that takes the fun out of cloning.
Nelson gave us enough details to start with, and 6moons photo's help. We now have some parts lying around, fire up the science lab and let's roll up our sleeves and go for it.😀
What about the tl431 instead of opto whatever???
I just dont have a good tl431 spice model that works,
Just a thought, El
I just dont have a good tl431 spice model that works,
Just a thought, El
hi everybody, 🙂
maybe I just heard half of the heaven J2 promises....
I got tea-bags semisouth and put them together with the semisouth I got from magura in a BA-1. I left the IRF240 on the negative side doing the job as a current source and ,like Nelson would say, not to spoil the performance of the output stage by the gainstage I changed the IRF610 by a semisouth R100.
Wonderful performance, more details, voices totally different and subtle.
So I can wait for J2 in any version much better! 😎
__________________
maybe I just heard half of the heaven J2 promises....
I got tea-bags semisouth and put them together with the semisouth I got from magura in a BA-1. I left the IRF240 on the negative side doing the job as a current source and ,like Nelson would say, not to spoil the performance of the output stage by the gainstage I changed the IRF610 by a semisouth R100.
Wonderful performance, more details, voices totally different and subtle.
So I can wait for J2 in any version much better! 😎
__________________