Anyone tried these? Sound samples? Thanks in advance. 
grol
IIRC, there were some more or less crappy U2be clips earlier in this thread?
Obviously the OP has tried out some.
All "puretube`s" circuits, schemos and "crappy" sound-/video clips until reply#77 are tested, measured 170/250 builds...
(and the reason/origin for this thread explained in 1st post & reply#8)
One of the fine options of the WWW is the clickability of hyperlinx... 
Another fine free thing for all non-illiterates* is the socalled topic- or thread-title (aka: "subject"),
which in this special case says: "Discrete..." as opposed to: "integrated..."
As mentioned in above post,
an explanation for the experiments with 2 complementary discrete MOSFETS was given in reply#8,
and will be repeated in the following quote,
for those who don`t wanna look past the first pic in a thread:
... came up with this coz I didn`t have non-SMD inverters at hand to quickly view...
So it should be clear,
that this whole stuff was not about "emulating tubes with fets",
but: "replacing a CMOS inverter IC with discrete MosFets"
(as far as my circuits are concerned).
And: it should also be clear by now, that those circuits are not an attempt
to make fets sound like tube-amps at all.
On the contrary:
I haven`t witnessed any (pure) tube-amp or (pure) tube-pedal outside my premises,
that would feature most of what those MosFet circuits do, soundwise...
*that come forum-crossing to this thread for the first time
pleez also see replies #24 & #38 for further understanding...