Krell KBL or Krell KRC-3 or neither?

In response to your question are tubes more suitable for the midrange. This is a personal preference and also somewhat system dependent. If you haven't what tubes do to the sound you should at least give it a listen at a dealer. The Krell KRC-3 is an excellent preamp and I doubt very much newer gear is any better especially considering the Krell's used price.

Being a new person you should read about room acoustics at realtraps.com or just do a google. You'll find your room the next most important component in your system. Money spent there can help alot. Without it you're not hearing what your system is capable of unless your room is great already. Odds of that are about 1 in a million. Well worth the education if you want to improve your system. cheers

You'll be surprised what a couple of bass traps and dampening all first reflection points alone can do. That's where I'd spend my money first. Then the dedicated lines are a good idea too. They won't help near as much as the room treatment will, trust me. I've been in this for over 30 years. Two prong outlets aren't going to hurt anything assuming your wiring is good. Something else you can do is go to the hardware store and put in some Pass and Seymour commercial grade outlets.

It's entirely possible you can connect the ground of the outlets to the box the outlets screw into and have a third ground. Get a polarity tester(5 bucks at the hardware store) and make sure you get the right wires in the right place. This will get you by. I'd still get the dedicated lines if you can afford them. I live in a 50 year old house and the wiring is good. Alot of it had been redone over the years and is upto new code. Learn about room acoustics and you'll be ahead of alot of people that have been doing this for years. It's cost to performance ratio is up there.