Comparison of JFETs for mic applications

[JohnRoberts]

If you are still working in the Audio field, they are not. Trust me on that.

I'm not, trust me on that.

That's terrible Latin. If you MUST be trite, please use:

NOLI PATI A SCELESTIS OPPRIMI

Thor

Quid agis hodie?

My apologies for dog latin, but I studied it 60 years ago....

JR

 

[thor.zmt]

Quid agis hodie?

litore habitantis
potator cervisie
persequens puellarum
excogitatoris singulari soni apparatu

My latin lessons are also long time ago.

Thor

 

[k brown]

k brown, you are right that the IBM/Lenovo ThinkPads are by far the most reliable. That's what I've been using so far but the last one died about a year ago. The T61 is the most powerful that had XP drivers. The later Lenovo TP series are not as reliable.

Which model ThinkPads have you got? If you can spare one from the early 90s, dis beach bum would be eternally grateful. Do any have XP?

Not sure how I can re-compense you unless you are making a Tetrahedral Ambisonic mike. If so, I can do a full alignment and calibration that you can compare with da 'general purpose' programmes .. or perhaps even Thors SupaDupa one

Something a mystery here; I had three, and the only one I can find now is an A31. It won't boot up because the mem batt is dead; I used to be able to manually put in the date and it would boot, but now I cen't get it do that.

The other two I can't find anywhere; my wife may have taken them to electronics recycling without my knowledge.

 

[k brown]

No, the J-Fet Library posted at the LT-Spice group of course. The one you need to sign up to access.



In the 2sk660 pdf.

View attachment 143448
As you can see, once we have > 2V across the FET, we are in saturation.



But we are not operation at 1V, are we?

View attachment 143449

I ran BAV99 in the sim, the results match @MicUlli 's test results, good enough for me.



Can do. If you insist. Not that it will change things.



There is nothing here not reasonably well understood for at least 5 decades. I'm still puzzled why we even have a debate.



Other than the Brownian motion noise of the capsule, which I will tackle once my office is set back up, I have confidence in my sims. The kind of confidence that comes from having simmed many dozens of circuits, taken them onto a PCB for mass production and having tested the result with AP2.

So thank you for concern, but it's misplaced.

Meanwhile, please post the circuits you want me to use for the "SimpleP48" and the "SimpleP48RCA" clfor a build in diode J-FET with Id(ss) = 370uA @ 10V.

I was digging around at the io group but gave up. Very poor SNR.

Thor

I purposely retain a certain amount of noise in my gear because recorded music is only emotionally moving because of Brownian Motion.

 

[Khron]

I purposely retain a certain amount of noise in my gear because recorded music is only emotionally moving because of Brownian Motion.

This one / this kind, right?

 

[micolas]

This one / this kind, right?