The End Of Big Iron?

I had a Rogue ST90 with KT120`s (100 Watt), sounded very VERY nice but I felt as though I needed more power for 'Those Occasions' and my Revel F52`s certainly can use up some power. But I was leery of pushing the tube amp too far.

I sold the Rogue and put a Class D Audio SDS-470 in its place (300/600 Watt) for the $$ the Class D 470 reminds me of the NAD 3020 I bought when it first came out.
I Used that 3020 with DCM Time Windows in a small room at the time and the combo was crazy good sounding !

This Class D Audio amp is crazy good too !! Plenty of power, runs cool, looks cool (silver w/blue leds) has great left-right imaging and nice depth and has bass power too.

But I`m realizing 'Those Occasions' don`t happen as often as I thought and I miss the small detailed subtleties, like the cymbals as they fade off/decay and other things that tubes are good at.

Anyway...Now I`m looking for a Rogue Atlas and I`ll keep the Class D here for those other occasions :)

I went from 100wpc tube amps to a pair of D-Sonic 600w mono amps after my power regenerator murdered them one fine morning. At the time, I was running 86db Snell speakers that I had bought with the amps back in 1991. I expected the new cheap class-d monos to be a serious setback compared to the Atma-Spheres, but elated when they turned out to be good as their generally HT customer base rave about, but it took me a long time and a lot of tweaking to get them to really fit well in my 2 channel system. But, with the right power cords and some reasonably good support under them, they can sound superb. These amps weigh about 10# each and are the same size and shape as a shoe box yet are capable of great things when the upstream system is singing sweetly.

I have no intention of comparing them with the Atma-spheres at the time. I have made scores of changes to the system since then, many of which would also have improved the sound of the OTLs as well, and if I ever find a few thousand "extra" dollars to have them repaired, I may put them back in service during the Winter months, but in the mean time, I'm not missing anything.

Just one last thought about the efficiency of the class-d amps. I calculated the energy cost savings for the 2 years following the change from tube amps. It was costing about $80/month for electricity to power the amps and another $50/month to run the air conditioning in the not-winter season here in Wisconsin.

Mcbuddah, what is wrong with your Atma-Sphere amps? Bad tubes?

A simple and inexpensive means of dealing with hot amplifiers, tube or solid state, is to install ceiling ventilation with ductwork to move the warmed air out of the building. This is very cheap to install and costs very little operate and is very effective! Air conditioning is rather brute-force.

"A simple and inexpensive means of dealing with hot amplifiers, tube or solid state, is to install ceiling ventilation with ductwork to move the warmed air out of the building. "

Installing new duct work is simple?

I guess its all relative.

Mapman, letting the heat coming off amplifiers escape to the outdoors can be extremely effective. Whether that requires ductwork depends upon the construction and what systems are in place. In other words if you are able to remove the heat there is no need to cool it, but you will need to make up the volume of air removed somehow.

My room with the big Sound Labs is pretty large. The Atma-Sphere MA-1s or MA-2s are perhaps fifteen feet away from the listening area, so the heat has some distance to travel, in which it blends with the room air. Although it is noticeable it's not bad. The HVAC system is generously oversized, so even with the big amps going and a dozen people listening, it's all good.

Mcbuddah, since you're in Wisconsin you might want to stop by one day for a visit. I have the M-60s in the downstairs system (essentially the system we showed at AXPONA a few weeks ago) in the much smaller room, and it's a very liveable, cozy and relaxed listening room.