Live and in the same screen as Nelson! So cool.
https://www.diyaudio.com/community/attachments/2bd13fc4-426b-4fbc-b69a-32141c97f7f9-jpeg.1100601/
https://www.diyaudio.com/community/attachments/2bd13fc4-426b-4fbc-b69a-32141c97f7f9-jpeg.1100601/
I thought there will be a line stage with gain from Nelson ?
https://www.diyaudio.com/community/threads/i-need-a-buffer-with-gain.390491/post-7129707
Any pointers ?
XACOO
https://www.diyaudio.com/community/threads/i-need-a-buffer-with-gain.390491/post-7129707
Any pointers ?
XACOO
That cannot be new idea, can it ? 🙂
https://www.passdiy.com/project/amplifiers/diy-op-amps
And if you use J113 as current source for the second stage, your rails are limited to +/-17V.
Unless you change to a depletion mode MOSFET.
Or add a cascode; or use 2SK246, (if you can find some).
Patrick
https://www.passdiy.com/project/amplifiers/diy-op-amps
And if you use J113 as current source for the second stage, your rails are limited to +/-17V.
Unless you change to a depletion mode MOSFET.
Or add a cascode; or use 2SK246, (if you can find some).
Patrick
When Nelson's BAF2022 talk is uploaded to YouTube, carefully listen to his audio (this isn't on a visual slide) discussion of J113s. He says he has built a fixture to test J113s and has been able to cherry pick large numbers of them which work correctly (according to his personal definition of "work correctly") all the way up to 70 volts. S E V E N T Y volts. I don't think he mentioned the Test Yield, i.e., #70V_parts_found / total#_parts_tested . Or if he did, I didn't hear it.
Presumably, other people can build test fixtures to do similar things, and extract their own stash of 70 volt capable J113s. Fortunately it's not costly to acquire a big pile of raw units to put into the test procedure.
_
Presumably, other people can build test fixtures to do similar things, and extract their own stash of 70 volt capable J113s. Fortunately it's not costly to acquire a big pile of raw units to put into the test procedure.
_
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The yield was 100% from several lot codes. The P ch parts are a bit lower and the Tosibas are lower, but there was no case less than 50 V.
Just a big thank you...
My first BAF was 2019, where I displayed a preamp I built, and met a lot of great folks, enjoyed a lot of great gear.
As a paid Zoom participant for 2022 which was very enjoyable, I was a lucky winner of an ACA Mini!
Thank you to Nelson, Tom, Jim, and everyone involved in putting together the kits, making them available to members, and giving some to BAF2022 participants. A special thanks to the hardworking crew that do so much to put these great events together and make them so interesting and fun.
I'll probably build this tonight, but still on the fence whether I'll put it inside a chassis box or not.
Cheers,
Greg
My first BAF was 2019, where I displayed a preamp I built, and met a lot of great folks, enjoyed a lot of great gear.
As a paid Zoom participant for 2022 which was very enjoyable, I was a lucky winner of an ACA Mini!
Thank you to Nelson, Tom, Jim, and everyone involved in putting together the kits, making them available to members, and giving some to BAF2022 participants. A special thanks to the hardworking crew that do so much to put these great events together and make them so interesting and fun.
I'll probably build this tonight, but still on the fence whether I'll put it inside a chassis box or not.
Cheers,
Greg
I tested them into 1K source resistors with the Gate grounded, so the
current was 2-3 mA, and I looked for the "knee".
current was 2-3 mA, and I looked for the "knee".
https://www.diyaudio.com/community/threads/lx-mini-crossover-article.324747/page-6#post-5554440
post #115
My 2x40Vdc Power supply was weak for destructive test.
post #115
My 2x40Vdc Power supply was weak for destructive test.
Ocasionaly it might be convient to use our precious 2sj74's at higher voltages too so has anyone done a similar test with them.
At BAF2022, I asked Paul Norton of Linear Systems to please start selling JFETs useful for bootstrapped cascode circuits. You want a large |Vpinchoff| and a large Vdg_max and a large Vds_max for this application. The old and now-obsolete J107 and J105 were pretty good for this application, if only their voltage ratings were higher. Paul said he would investigate.
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Chicken ZM, like to control Vds of cascoded JFets
Slept with Papa Borbely papers month or so, in the end chickened both of White Cascode Follower and from JFet (high Vpinchoff) cascodes
aha, from current diodes too
from laterals too
from Preputium made of JFets and Mosfets in regs
though, still having DH101 driving Bose Roommates
Slept with Papa Borbely papers month or so, in the end chickened both of White Cascode Follower and from JFet (high Vpinchoff) cascodes
aha, from current diodes too
from laterals too
from Preputium made of JFets and Mosfets in regs
though, still having DH101 driving Bose Roommates
With this control of cascode, you remind me of JC, he uploaded his JC2 schematic and put ??? on cascode control elements 🙂Chicken ZM, like to control Vds of cascoded JFets
I bet no body tried to find values 🙂
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