4 ohm vs 8 ohm taps

inpepinnovations@aol.com...The primary impedance depends greatly on the secondary loading. If it didn't why would transformers have multiple taps?

inpepinnovations@aol.com...You have it backwards. The different taps of the transformer secondary make it possible for the tubes to see the same (high) impedance with different loads.

Here is a way for you to test your theory. Short out the speaker terminals of your amp and drive it hard. If your theory is correct, the tubes won't see the short. After the fire department has left, post results of this experiment :-)

inpepinnovations@aol.com...How can you say that a zero ohm load is "seen" through transformer coupling, but yet loudspeaker loads are not?

In another area, when you use a step up transformer for your moving coil phono pickup it can be connected to a standard MM preamp input, 47K input load, and still present the proper loading of a few hundred ohms on the pickup. The loading applied to the secondary is "seen" through the turns ratio of the transformer.
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inpepinnovations@aol.com...An 8ohm speaker on the 8 ohm tap, and a 4 ohm speaker on the 4 ohm tap will look the same to the tubes driving the primary. (That's why different taps are provided). If the 8 ohm speaker is on the 4 ohm tap or the 4 ohm speaker is on the 8 ohm tap the tubes will see an impedance that is not what the amp designer wanted. Whether this will be enough to cause significant distortion, and if so, how much, is a question I will leave to the amp designers like Atmaspere.
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inpepinnovations@aol.com...You say quite plainly, "The tubes continue to see the primary winding impedence, whose impedence remains constant regardless of what impedence speaker is attached to whatever tap". It is not a question of misunderstanding. You are wrong.

How do you explain the MC phono pickup step up transformer example?

inpepinnovations@aol.com...Have a nice day.