Does a discrete opamp such as the API 2520 reverse polarity?

[Coldsnow]

Does a discrete opamp such as the 2520 reverse polarity?  The reason I asked, is that it seems on the 325 card the output transformer is reversed possibly reversing back, or am I reading it wrong.

 

[JohnRoberts]

Opamps are bi-sexual... the feedback network around them determines if the polarity gets reversed or not.

JR

 

[Coldsnow]

So in this schematic http://www.waltzingbear.com/Schematics/API/API_325.htm
Am I reading it correctly that the output transformer is wired to reverse polarity?

 

[Bo Hansen]

Coldsnow,

2520 is a common OP amp with a (+) non inverting input and a (-) inverting input.
If the input signal is connected to the (+) non inverting input, it will be in the same phase on the output.

This met the 325 card, and also the output transformer is connected in the correct phase, but on the 312 card is the output transformer primary and secondary side connected out of phase, as indicated by the transformer windings in the schematic.
But as both primary and secondary side is phase reversed, it becomes still right in the end.

The reason why they did this, I have no knowledge of.

--Bo

 

[Coldsnow]

I guess that is where I am confused.  On the 312, it looks like both the input and output transformers are wired out of phase the output reversing the input.  Is this correct?

 

[Bo Hansen]

The mic transformer windings on the 312 card is connected in phase.
(look at the windings dot)

--Bo