I would think it would be hard to compare the zeus and cat with the atmasphere amps as it would be transformers vs OTL;which are 2 completely different species of amps with completely different designs.
If you were driving a 16 ohm speaker my money is on ralphs design (atmasphere) and I think it would win hands down over the other 2.
If the speakers impedance curve dips below 4 ohms I would think it would be a very close match with the CAT probally winning; thats my opinion though.
You should compare for yourself and see what happens;probally would be a good learning experience.
If you were driving a 16 ohm speaker my money is on ralphs design (atmasphere) and I think it would win hands down over the other 2.
If the speakers impedance curve dips below 4 ohms I would think it would be a very close match with the CAT probally winning; thats my opinion though.
You should compare for yourself and see what happens;probally would be a good learning experience.