AudioBanter.com - View Single Post

Chris Hornbeck wrote:
On 30 Jun 2005 20:58:00 -0400, (Mike Rivers)
wrote:

So, why must a triode design inherently have more local
feedback than any other?

I was wondering about that term "local feedback" too. It sounds like
one of those terms coined by the same folks who talk about LDC and
SDC. Is it some hip name for not bypassing the cathode resistor?

I'm halfway trying to tease Arny into making the effort to
convince me about the "internal feedback" model of active
(transconductance) devices, which I'm too much of an old grump
to accept casually, and halfway making a serious argument
about gain-staging within feedback loops.

I suppose you could think about any amplifier stage as being an amplifier
of infinite gain combined with degeneration. That's a useful thing from
the standpoint of theoretical modelling.

But, you can also think of a power supply as being a voltage source with
zero impedance in combination with a series resistor. But that's not
actually what's inside the box of my Sorenson here.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."