John Byrns wrote:

In article , Pooh Bear
wrote:

Phil Allison wrote:

"Poopie Bear"

Once again I'm not talking about an OTL design.

Simply the transformer in the cathode circuit. No voltage gain. Inherently
flat frequency response ! Much more linear.


** A power triode inherently has a flat response from DC to hundreds of KHz.

With a *pure resistive* load - yes.... The impedance presented by a
transformer
loaded with a loudspeaker is *anything but* pure resistive however !

With a reactive load in the plate circuit the gain will be approx proportional
to the load Z. Hence any variation in Z leads to a variation in gain and hence
changes in the amplitude/frequncy repsonse.

That's *basic* stuff !

The same is true of transistors, just substitute the word collector for plate.

Regards,

John Byrns

If transistor amps were collector loaded - then yes.

Most audio SS amps today use an emitter follower output. That arrangement simply
doesn't care about the load Z. It's important that the emitter follower has enough
current gain though ( use darlingtons or triples ) or the load might still 'reflect'
back to the previous voltage gain stage and possibly cause stability problems (
usually phase angle related ).

Those that do have a collector load use serious nfb to correct the issue of response
errors.

Graham