Which Component Needs to be Upgraded First


I need your help. I am looking to upgrade a component in my system. My question is which of the components is the weakest link and should be the first to upgrade. source: Sony 333es SACD, Pre-Amp hand built by Veda Audio - Dyna Hi Kevin Gilmore design, B&K ST 140 amp, Talon Audio Khorous-X speakers (the speakers are not going to be considered for upgrading. Thanks for your wisdom.
gunting
IMHO, and at the risk of telling you something you already know, once you've reached your level of components, and especially since your're not considering a speaker upgrade (and I'm not suggesting that you should consider it), the only way to tell is to demo a piece--source, amp, or otherwise--in your home w/ your equipment. Beware of assuming that a newer, more expensive component will give you an upgrade in sound.
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I reccomend you get power straight first,cond,cables,ect.Every other thing after that.imho.
I must admit that I am not a firm believer that significant differences can be achieved via the "right" cables, power cords, and power supplies. It seems like most folks responding to this post suggest upgrading source and amp first. I have taken the first step, and added a DAC right behind the Sony SACD 333ES player. My impression is that that the music improved in clarity and crispness, particularly in bass and mid range representation. I will look around on the Audiogon boards for a good amp deal. Thanks to all for taking the time to help me.