What is the point or trick of those serialized/cascaded J-FETs (Q1, Q2)?



Can anybody name or explain this technology, please?

Can somebody help me finding "Roland Blues Cube Hot" schematic?

(PS: Sorry for the confusion and my extensive editing my postings. I did not know the "Hot" is a DSP modeling amp, I'm looking for the old all-analog - non-DSP version)

What does 1M10A pot mean? There are other pots called 1M20A...
1.10 MOhms, analog taper (log)? And 1.20 MOhms, analog taper (log)?

Wanted: EVH 5150 III 100S Stealth Head schematics
Can anybody help?   
I found 5150 III 50 schematics but the 100W head has separate EQ and resonance control for each channel...
PS:
Problem solved:
This link helped via wayback machine:
https://music-electronics-forum.com/showthread.php?t=19518&page=2&p=440260&viewfull=1#post440260
Direct link:
http://web.archive.org/web/20161115042749/http://www.evhgear.com/support/

Hi,
I like the sound of 5150/6505, SLO100, hot rodded marshalls and similar tube amps, but I don't like all the tube typical disadvantages (heat, wearing, microphony, weight, costs, high voltage...).
So I am looking for solid state alternatives to tube amps and found some interesting circuits using depletion MOSFETs (LND150) by KMG and others.
I'm not quite sure if I need a tube or tube emulating FET output stage using a big output transformer to get that overdriven sound by the output stage, or if same or similar sound could be generated in the pre amp section. If possible I'd like to use a "normal" transformerless transistor final stage to get rid of the weighty and expensive output transformer. I'd also want to get rid of higher voltages >>60-100V.
Does anybody know if there's a chance?
I'm electronic technician, but I'm not an electronic developer, so I need a little help by the amp experts here...