For the last several months I have anxiously awaited a Megatron to pair with my x9000s. So far I have listened with a Carbon and a 323x. I tolerated x9000s with 323s...I liked x9000s with Carbon...Megatron arrived two days ago. I plan to post very brief impressions on Head-fi and the other site.
My builder is Soren Brix, and I would not feel comfortable sharing any of my listening experience without first giving credit to Soren. I'm new to the hobby and so I cannot really make comparisons, but my experience with Soren made the amp-building experience personal, intellectually stimulating, and (of course) fun. I recommend him as a builder and as a person without hesitation.
I will keep the 323x as a fallback option in case my Plan A isn't working for whatever reason. It's fine but mushy. It has connectors that the Carbon and Megatron don't. That's nice.
I might keep the Carbon--I don't need it, but certainly I will keep it for the near future. It's as lucid and precise as I can imagine an amp being. I think it's a good fit for any number of headphones due to its clarity. I like it with the x9000s and I'm considering getting a 007 mki, specifically to pair it with the Carbon. It's idiot-proof and much of my classical and acoustic music is having a field day.
I love the Megatron. It rocks with pretty much everything I listen to. I'm not a millionaire--money matters, and I'm nearly out of mine. Of course the Megatron is more expensive than a Carbon. It's worth the extra expense. I won't try to pretend to be technical: the Megatron is FUN. I officially have a bias towards tubes. I doubt I'll ever be able to afford a T2, or any of that Shangri-la business. That's fine. I think I can live without a top-of-the-top-of-the-line because I have a Megatron, and it makes the x9000s a joy to listen to without fatigue.
A few comments about some claims I've read about Megatron:
The Megatron does not run too hot. It's warm and that's it. It is not a hazard or a danger or a space heater, unless you like juggling hot tubes while covered in petrol.
The Megatron does not need an hour to warm up. It takes one minute. I do not understand where this claim originated from.
The Megatron does not need a priceless collection of tubes to roll. Mine are stock Mullards and a pair of Philips E80CCs. A couple hundred euros and you're done for the next 10,000 hours or so. The sound is fresh, full, vibrant, intimate, and, again, fun. I might venture into tube-rolling someday, but not anytime soon.
I might have more to say about the Megatron and x9000s, but that's enough for now. Thank you Soren!