The End Of Big Iron?

Onhwy61 maybe it's not big deal on 1kHz, but bigger on other frequencies depending on speaker. If you plan to install Meyer Sound arrays in your listening room, than probably you'll feel difference.
For average home rooms and speakers It's not big deal anyways.

I think that megawatt power amps were necessary if you could afford them + you had a big enough room for them to perform to their max to create outdoor concert-level SPLs.

I seem to also think that megawatt power amps are dwindling due to the economy. These amps require huge power transformers & just the weight of these power xformers necessitates the use of thick metal for the chassis & huge heatsinks. That's a lot of machined metal that costs a pretty penny. Many people are not going to spend that kind of money anymore given the way the economy turned in 2008.

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Big Iron may just become a collectors item. I used to peruse the 'for sale' items here on the 'Gon for Big Iron just to see what was available. There used to be much more of it available. Now you don't see much of it here any more in the 'for sale' listings. I think the owners may be holding on to it. I have a big room and big speakers, but I do plan to give Class D a shot to see what all the fuss is about.
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I'm into monster Class A amps instead of A/B; Accuphase, Pass Labs, etc. Class A just sounds better. :D

@mitch4t, I think you may like what you hear from class D. I used to have what, to me, was "big iron"...an ATI1506 6x150 amp. Not huge power output like you guys are talking about, but man I hated having to move that thing. Threw off a lot of heat, and was just onerous. Felt like it weighed 75 pounds - maybe it actually did. I bridged it to put out 450wpc into my home theater fronts, but had to sell it when my business turned down in 2008. I did regret selling it, and wished I hadn't for a long while - it just looked so cool (when I wasn't trying to relocate it).

Fast forward, and I now have a Peachtree Grand Integrated running a pair of WB Arcs - power overkill for sure, but I've got 440wpc on tap, it's the size of a small stereo receiver, and barely gets warm. And the sound is absolutely luscious. It's amazing that so much power can come from something with such a nice footprint, without much heat thrown off. I admit - I still think "big iron" amps look so cool, but there's something to be said for one's audio equipment not dominating your living space - before I bought the Peachtree I almost bought a Bel Canto, so nice looking with such a small footprint. I like that trend.