Here is a little buffer using depletion mode BSP129 SMT MOSFETs.
It will drive low impedance loads at .000% thd range. Frequency response is very extended to video range.
It needs some heatsinking or lots of copper because the current is close to 100 mA.
The circuit is the old White video buffer with silicon.
It will drive low impedance loads at .000% thd range. Frequency response is very extended to video range.
It needs some heatsinking or lots of copper because the current is close to 100 mA.
The circuit is the old White video buffer with silicon.
This is really cool! And impressive bandwidth and drive capabilities. Will it knock out my p2p B1R2 I wonder!
Will there be boards?
Will there be boards?
For those interested in circuitry, here is a good reference about the White follower and alternatives.
https://www.tubecad.com/2004/blog0023.htm
The White follower has poor PSRR to the positive rail.
One alternative is the Taylor follower.
(See description at the above link to tubecad.)
We did similar with LU1014 triode cell instead.
www.diyaudio.com/community/threads/the-dao-se-all-fet-class-a-zgf-headphone-amplifier.225577/
Cheers,
Patrick
https://www.tubecad.com/2004/blog0023.htm
The White follower has poor PSRR to the positive rail.
One alternative is the Taylor follower.
(See description at the above link to tubecad.)
We did similar with LU1014 triode cell instead.
www.diyaudio.com/community/threads/the-dao-se-all-fet-class-a-zgf-headphone-amplifier.225577/
Cheers,
Patrick
not having experience with BSP129, nor believing blindly in LTSpice, I'm just puttin' mild question mark here ......
Are there any p channel depletion mosfets available ?
And n channel in "regular" cases as Ada suggests ? Thanks.
BSP seems to be an old Siemens part designation. Not sure this is still true today.
And n channel in "regular" cases as Ada suggests ? Thanks.
BSP seems to be an old Siemens part designation. Not sure this is still true today.
Come on Fellas, I thought this was the FAB club?
BSP129 is easy to solder!
Don't let a little SOT-223-3 make you shake in dem boots.
BSP129 is easy to solder!
Don't let a little SOT-223-3 make you shake in dem boots.
I checked and it is about 90 mA's. Simulation is okay but solder is best.
It really likes current for performance. Two volt output @ 1KHz is .0003% Thdn -.2 dB @ 200KHz
It really likes current for performance. Two volt output @ 1KHz is .0003% Thdn -.2 dB @ 200KHz
