4/8/16 ohm tabs for Negative Feedback

[psychepool]

Many amps have negative feedback on their poweramp and have been applied to many of the amps I have made.
However, when there were several impedance tabs in the output transformer, each circuits had different choices of tabs that drew feedback.(even almost similar circuits too)

Many amplifiers seemed to select a lot of 8ohm tabs and a lot of 4ohm tabs were also used. The 16ohm tab seemed to be rarely used.

In my opinion, it seems fair to draw from the other side of the selector(the output jack tip), not from the impedance tab.
But I have never seen anything drawn from there.

Is there any reason to choose a specific impedance tab for NFB configuration?

[martin manning]

Is there any reason to choose a specific impedance tab for NFB configuration?

Yes. That keeps the feedback ratio constant regardless of which output impedance is selected.

[pompeiisneaks]

Or, for more detail, each tap needs a specifically calculated resistor to set the NFB correctly, if you put it at the tip you'd also need some kind of resistor switch that the user would have to make sure to manually set with the specific ohm's setting they were using, which would not be easy and something people would forget.

~Phil