Cloud Lifter (Custom Circuit) Newbie Question

[jim_griff]

So, as a total newbie to JFETs (and basically electronics as a whole), I'm trying to design something akin to a Cloud Lifter - a device used to pre-amplify a dynamic microphone's signal to a decent level before the proper preamp stage. It uses 48V phantom power to power the circuit. I believe Phantom power is usually fed via 6.81k resistors to both the hot and cold signal wires to the microphone. In this case, that 48V isn't usually needed for a dynamic mic, but is instead used to power the JFETs in the circuit.

Pic 1 is my circuit.
Pic 2 is simplified circuit.
Pic 3 is also the same simplified circuit but different arrangement.
*Topologies are the same, just arranged differently so you can see how it's all connected.

My question is this: How on Earth does it work to amplify the signal? I can't for the life of me figure out where the gain comes from.

I can't find anything online where people have JFETs in this configuration. i.e. "Back-to-back", or I guess a kind of Darlington Pair but with the power connected to different terminals...

Apologies for such a newbie question, but if anyone could point me in the direction of good resources for JFETs, I'd very much appreciate it! Cheers.

P.S. Pics 4 and 5 are the generated outputs of the TINA-TI simulation. It seems to work, but I'm going to order some JFETs in the meantime so I can make up a PCB in a week or two.

[Ian.M]

Its a differential modified cascode: https://en.wikipedia.org/wiki/Cascode
Instead of grounding the Gate of the upper FET, its connected to the lower FET Source so it to a large extent tracks the input signal maintaining the Vds of the lower FET more nearly constant.  Pic3 shows this most clearly.   

[jim_griff]

Thanks so much Ian! I'll have a good look into Cascode designs. Something I've heard of before but never looked into. Had no idea this was anything like that.

Thanks again. Really appreciate the help!