Why are some Amps so heavy? Are they better? Are Toroidal transformers must be the best?

[Steve81]

I find it more understandable with the ATI as you can see the Power/Weight ratio improves drastically as you move up their product line. Going from the AT602 to 1202 you get double the power but only 4 lbs (12.5% increase) more in weight. So while the 602 seems heavier than normal, the 1202 appears more normal. The 4 lbs gain is probably due 99% to the larger transformer and heat sinks.

In the case of ATI, it probably helps that they're reusing the same compact chassis, and potentially some of the innards as well.

Jumping from my XPA-200 to the big boy XPA-2, you're theoretically only doubling power, like with the 602 to the 1202, but realistically its a bit more than that given that the 200's output is rated at 1% THD+N versus 0.1% THD+N for the XPA-2. In terms of hardware, the transformer is much heavier (1200VA vs 360VA) as well as housed in it's own little compartment, and the boards containing the output stage run practically the full length of amplifier and are paired with pretty hefty looking heat sinks which also run the full (abnormally long) length of the amp. Heck, on that last point, I'd bet the XPA-2 has more sheer metal in one of its heat sinks than the Outlaw 7125 pictured below has on all seven of its channels.

 

[PENG]

In the case of ATI, it probably helps that they're reusing the same compact chassis, and potentially some of the innards as well.

Jumping from my XPA-200 to the big boy XPA-2, you're theoretically only doubling power, like with the 602 to the 1202, but realistically its a bit more than that given that the 200's output is rated at 1% THD+N versus 0.1% THD+N for the XPA-2. In terms of hardware, the transformer is much heavier (1200VA vs 360VA) as well as housed in it's own little compartment, and the boards containing the output stage run practically the full length of amplifier and are paired with pretty hefty looking heat sinks which also run the full (abnormally long) length of the amp. Heck, on that last point, I'd bet the XPA-2 has more sheer metal in one of its heat sinks than the Outlaw 7125 pictured below has on all seven of its channels.

I agree those heat sinks look heavy. Again, its the design, other designs would likely allow for much lighter ones.

 

[Steve81]

Again, its the design, other designs would likely allow for much lighter ones.

Indeed. I'd bet one of those heat sinks could probably compete with the entire weight of a Crown XLS 2500

 

[SonomaComa]

I Really like the specs on that XPA-5.

 

[SonomaComa]

And it seems like Emotiva does not skimp on the materials. Plus they claim it does produce 200 watts of power to all channels all the time, not just at the peaks. XPA-5 | 200W x 5 | Emotiva Audio | High-end audio components for audiophiles and videophiles, spanning 2-channel music systems, as well as 5.1 and 7.1 home theaters. Products include multichannel amplifiers, stereo amplifiers, and monoblock amplifier