IIRC Cliff has once stated that when changing the power amp (PA) tube type the virtual output transformer is also changed to match these tubes.
That's something you wouldn't do on a real amp as it would require you to actually swap out the transformer. And that's the main reason why changing real PA tubes often leads to drastic tone changes. It's not the tubes themselves but the mismatched transformer. When changing the tube type in the Axe Fx the difference in tone is quite negligible because of the transformer being matched automatically. To get the same results as on a real amp you need to actually mismatch the virtual transformer using the Transformer Match value.
I think it would be cool if the Transformer Match value would automatically change to reflect the mismatch caused by changing the tube type WITHOUT changing the transformer. If one would like to have a correctly matched virtual transformer he could just set the value back to 1.
That's something you wouldn't do on a real amp as it would require you to actually swap out the transformer. And that's the main reason why changing real PA tubes often leads to drastic tone changes. It's not the tubes themselves but the mismatched transformer. When changing the tube type in the Axe Fx the difference in tone is quite negligible because of the transformer being matched automatically. To get the same results as on a real amp you need to actually mismatch the virtual transformer using the Transformer Match value.
I think it would be cool if the Transformer Match value would automatically change to reflect the mismatch caused by changing the tube type WITHOUT changing the transformer. If one would like to have a correctly matched virtual transformer he could just set the value back to 1.