Amp vs. preamp

Hopefully, your expertise can help me out. I can not stop upgrading and i'd been thinking about this for some time. I am relatively new to this hobby and have heard many things regarding amps and preamps. What is more important in the overall scheme of things for home theater and music. The amp or preamp assuming you have really good speakers. Would you guys invest more money into 5.1 processor or the amp? Seeing a lot of these used high end gear in reasonable prices is so tempting to upgrade. I use my system for both music and movies. I also realize room acoustics makes a big difference but i will worry about that later in terms of treating it.

1) Will there be a noticeable difference if i was to step up to a used krell preamp vs. my rotel 1068

2) Or use my rotel preamp and get a better amp.

If the difference is considerable, i might go in that direction. Or just be happy with what i have. Im using revel performa speakers right now.
I subscribe to the "garbage in, garbage out" school of thought with respect to upgrading. Start at the front and then work your way down the chain: source, preamp, amp, speakers in that order. Good downstream equipment cannot add what is lost upstream. The best that it can do is offset an upstream deficiency. It's better if there is no deficiency to offset, or as small a one as possible.

Now if you happen to come across a good piece of gear at a good price, I would also suggest that you be practical and take advantage of the opportunity even though the upgrade may not be in the right "order". This presumes, however, that the upstream components will be upgraded shortly thereafter. Otherwise, you're spending money on downstream components whose potential will not be realized without correspondingly good upstream components. A bit of a waste of money.

By the way, you have said some dangerous things.

"I can not stop upgrading".

Also: "I am relatively new to this hobby and have heard many things".

I am a bit worried that you don't know why you're upgrading other than that it seems to be the thing to do. You haven't really identified what you're unhappy about.

Step back and take a deep breath. Your pocketbook will thank you. If you just go out and upgrade without a clear plan, you are likely to buy something which doesn't do what you hope it will do, or you will not hear it do what other people say it will do. This will turn you off to the high end very quickly.

Take you time and learn a bit. Ask yourself what you're unhappy with before upgrading. Research some threads and get a feel for the character of equipment you're interested in through the experiences of others, And most importantly, listen to things yourself at your local stores. Then you can begin upgrading with a clear idea of what you want to do and what equipment might be the best match.
there is no definitive answer. however, the preamp is closer to the source, so in that sense,getting a "good" signal to the amp is very important.
Rot this is probably an easy decision to upgrade the source. Although you don't mention your specific amp, realize that your downline components depend upon a quality upline signal in order to really perform. A quality amp + speakers is still no better than the (marginal) source that drives them. So start at the beginning. The room can wait (unless of course you have some major issues in that regard).
Case in point: I use a $10K pre to drive a $6K amp + $4.5K speakers.
Im currently using a rotel 1075 amp. Its a great amp for the money but i know there are a lot better amps out there.
Your suggestions help a lot. I just happen to have some disposable income right now and would like to put together the best system i can within reason. Markphd, thanks for your response as this puts some perspective/direction into my head.
you may not need to upgrade at all.....sometimes even the finest gear won't give one satisfaction. indulge in other things for awhile then come back to it.rotel is great gear, and changing components is a game of inches. all that great gear you see for sale is either there because of disatisfaction or a need for money. take a few weeks or months and decide whats important to you.
Lots of good suggestions here. I would throw in that the preamp/amp is a combination and should be considered together. Now you have a Rotel pre/amp combo that is probably very equivalent and compatible. If you upgrade one and not the other, you may see little gain. Even if you can't buy both at once, an upgrade path is good to have. Also, to me, the difficulty in buying used gear is typically that lack of ability to audition with your own gear. If you are happy with your Revels, perhaps you could get a feel for the type of pre/amp that works well with them to yours ears: neutral, warm, SS, tubes, etc. Then you could post "Neutral SS amp recomendations for $X". Personally, I like to start with speakers and move upstream. Others make valid points - garbage in, garbage out - but to me, the speakers have the largest impact to the overall style of your sound.
Like Sgower I like to start at the speakers and move upwards as my speakers being maggies, amp choice is based on that. I am very familar with your amp + pre. as I had the 1066 pre. + 1075 amp. and it did a great job on 5.1 + movies but I listened to 2 ch. 98% of the time and in 2 ch. mode it just didn't quite cut it for me compared to a good 2 ch. setup. Cost was also a factor as I was on a bugdet and prefered to have my $$ in a Better 2 Ch. system. I sold my Rotel gear an moved back to a Better 2 Ch. setup and also got a older Pioneer Elite Receiver to do the 5.1 duty for Movies. To me it was a Matter of what was more important to Me 2 Ch.Music or 5.1 because I couldn't afford to do both at the level I wanted.
Like you I found the 1075 amp to be very good for the money and even used it in my 2 Ch. setup for awhile. But found fault with the 1066 Pre. for 2 Ch. Music. If you stay with your 5.1 setup I would look at a upgrade to the Pre. But I would also take your time and do some reseach on different Processors and ask more questions on different forms as well. If you can find a Processor that does a great job on 2 Ch. Music you will have have a great system for both. There are some great deals on some used gear out there but take your time to make the right choice, don't rush into it.