To expand a bit upon the above posts and my own post regarding the CAT amps and their transformers and power supplies, the original CAT JL-1 100 watt/channel monoblocks are gnarling beasts. They contain outrageous hand-wound transformers that weigh 55 lbs. each, the power supplies are something like 1,000 joules per monoblock, and each monoblock weighs 192 lbs. By comparison, the "monster" 500 watt/channel Audio Research 610T monoblocks weigh 170 lbs. each (as transformers and power supplies are both heavy and expensive, the quality of a tube amp can largely be gauged by its weight and cost). I almost stripped a gear helping my friend carry his JL-1 Limited Edition's from one side of the room to another.
Speaking of the JL-1 Limited Edition, it was point-to-point wired and had unbelievable parts quality - it retailed for $50,000 and Ken Stevens only made about a dozen of them (not to be confused with later "Signature" versions of the JL-2 and JL-3 that use circuit boards and cost $20k less). It has incredible finesse and resolution, but at the same time, sounds subjectively more powerful that a 500 watt/channel Krell. I am not aware of a more potent tube amp or a better sounding high powered tube amp. All of that said, like a Shelby Cobra, it was high maintenance and frequently blew output tubes, which took out resistors that had to be soldered out and new ones soldered in - my friend nicknamed them the "Popcorn Poppers" and would not leave them unattended.
Speaking of the JL-1 Limited Edition, it was point-to-point wired and had unbelievable parts quality - it retailed for $50,000 and Ken Stevens only made about a dozen of them (not to be confused with later "Signature" versions of the JL-2 and JL-3 that use circuit boards and cost $20k less). It has incredible finesse and resolution, but at the same time, sounds subjectively more powerful that a 500 watt/channel Krell. I am not aware of a more potent tube amp or a better sounding high powered tube amp. All of that said, like a Shelby Cobra, it was high maintenance and frequently blew output tubes, which took out resistors that had to be soldered out and new ones soldered in - my friend nicknamed them the "Popcorn Poppers" and would not leave them unattended.