2 channel system?

You should go with the best source (cd or turntable) your budget can afford. No matter how good is your preamp or integrated, they only will amplify what you feed them. In all of my years in this hobby, over 25, an upgrade in the source always have gave me a noticeable improvement in sound quality. Upgrades in the preamp and the amps will give you improvements, but more subtle ones. Go to www.linn.co.uk there is a good explanation on how even the best preamps and amp can't improve a low quality signal.

Hepl offers a good rule of thumb. However, it depends on what components and speakers we're talking about. If your source is pretty good, but your amp is very weak, you could realize a more noticeable improvement by upgrading the amp. Every system is different.

rule of thumb is you can't hear what doesn't exist... buy the best source you are able to afford so that if the software has the info the hardware can read it and send on down the line.

Linn was very influential in developing the theory of priority that went beyond the foolish 50% on speakers syndrome that used to be so popular. The source is far and away the most important! If you don't get the music off the source, LP or CD, your componants will not add it back later. Buy the best source you can afford and work your way back to the speakers. Don't forget to have fun though!

All very good suggestions. But don't forget about speaker cables and interconnects, either. As someone who first started out with lower end Monster, MIT, and XLO cables and is now using mid-line Transparent and Audioquest cables; the differences can be quite amazing. Your music takes on a new dimension; and details you never heard before are clear and prcise. And as Nrchy mentions, do have some fun and enjoy the great music!