Negative feedback, voltage and output impedance

Output impedance in tube amp solely depends on output transformer except cases with OTL where the complicated circuitry applied for the output stages to decrease an output impedance.
Negative feedbeck realy doesn't care for tubes or SS and neccessary to increase the freequency bandwidth and decrease harmonic distortions.

Bombaywalla,
If setting sais @0, it doesn't mean that the negative feedback is 0.
Without one, I doubt that any full range amp is produced. The differential input stages(usually dual triode connected as such) imply the stage with 0 gain and 100% negative feedback. The output stage may than be a feedback free... again, with some degree of sacrifice to load capabilities. With tube OTLs it's simply impossible.

The difference between Atmasphere and McIntosh is that Atmasphere wants to make its product more marketable spreading a gossip that less feedback is always better.

I think that simply saying no feedback means nothing since there are many different kinds of feedback that manufacturers may describe in plain English just like Eldartford did.

Feedback circuitries is the whole separate topic and must be clarified in terms of what feedback is present and what feedback is not. Simply saying "no feedback" lacks the helluva information and knowing just from words on paper that amp has no feedback doesn't mean that it will sound better than the one with.

Amp's input and driving stages do definitely have a feedback so the statement "no feedback" isn't truthfull in any case. All the author of the post wants is just a truth about feedback and why it's "so bad and negative".