Common base VAS

[Stee]

this amplifier is a modification of a-680 diyGene.com
is an inverting amplifier
so don't need current mirror
I have connected jfet source on GROUND as tube's design
that works very fine

DIYGene - Electronics DIY, Hi Fi , amplifier

 

[CBS240]

If you take away the summing node and make it gnd, the diff amp is no longer a diff amp. You have two common source amplifiers, with different transfer characteristics and distortion spectrum. If it works it works, but it is nothing particularly special. Symmetrical folded cascode VAS. Is there a different perception of the sound after swapping the input stage?

 

[Stee]

yes of course

never listening a better amplifier
probably because don't have differential stage
or because have ground reference like triode (not so easy to found)
also because I have simulate internal balanced power supply
with two transformers in input
one of these do an inverting phase
and the same again in output polarity

in other words

to get the advantage of balanced sound
without risk of adding errors
just take a power transformer as input converter

you can simulate the natural balance of power supply like true balanced AMP
inverting a channel input (secondary polarity) and output (loudspeaker)

 

[Stee]

see a ZOOM

of input and VAS stages