Need the best amp

[Irvrobinson]

In theory it is not possible to double down due to losses that increase with current, if for no other reasons, but amps like Krell's, Bouders etc., can get very close. I suspect in practice most simply rate their output into 8 ohms conservatively and then rate their output into 4 ohms more naturally or aggressively to give people the impression that they double down. I think Irvrobinson might have implied that too in his post but I am not sure.

That is exactly what I was saying. Under-rate at 8 ohms and be more accurate at 4 ohms, and it looks like you double down, when in reality it is just specmanship.

My old Levinson 334s did indeed double down, but if you popped the lid you saw massive over-engineering to support that. Twin 800VA transformers for only 125W/ch into 8 ohms. Caps the size of Coke cans, with 176K microfarads of capacitance. Two fully differential complimentary pairs of bi-polars per channel. Buss bars rather than wires. Predictive dynamic bias level to keep the transistors in Class A efficiently. Very cool to look at, especially if you knew what you were looking at, but in retrospect definitely an amp for someone with more money than sense. (But silliness can be fun.)