Whats more important, source cables or amp cables?

I'd like to save some time demo'ing my own system for hours and get some experts to tell me what to do. What's most important, the cable between the source and the pre-pro, or the pre-pro and the amp(s). Does it make more difference in the sound to place my better pair of XLRs before or after the pre. I have a small Krell system, DVD Std, HTS 7.1, and 2250/3250 KAVs. I asked Krell and he told me they are both important, but that didn't really help since finding another pair of Crecendos is easier said than done. I have one pair, and 2 pair of Serenades, which don't suck, but from what I've read, aren't near as good as the Crecendos.

Any help or explanations would be beneficial at this point. Thanks AGers
Hope your ready for a slew of different answers. IME in two different Mcintosh systems with a least 3 different CDPs the pre to amp made the most improvement when using the better IC between the two. It is contrary to logic as one would think the source is the start of the chain and most vulnerable to IC changes. All I can conclude is that a source is a stronger signal than the preamp signal which is at a lower variable signal. If running at very high or full gain maybe it would be a different outcome, but who would want to.
Since you already have the cables, why don't you try them out and see which way you like better?
Anywhere you loose the information you have a problem.A prime example of your only as good as your weakest link.
This is really system dependent and there is no true answer to your question. You really have to try for your self. You may even find that you hear no difference at all
They're all important, but I say amp to preamp first.
I just finished trying out a number of xlr cables, swapping them out between equipment as you want to do. I found that the cables between the pre and the amp affected the sound more then the ones between source and pre.
This is probably because they are the last in the chain.
Don't know if this is any help or not.
Yep! use the advice above.
IMO there is unfortunately no way to predict the answer to your question, in part because there are many component-dependent variables that will influence the behavior of the cables in each location. A couple of examples, among many, being the output impedances of the components, and the susceptibility of the components to ground loop effects. A "better" cable will not necessarily provide better performance in any given location, depending on how its characteristics interact with the characteristics of what it is connecting. Also, "better" performance is not always subjectively preferable.

In your specific case, though, your connections are balanced, and I suspect that the components have low output impedances. Those two factors will in general tend to reduce cable effects, everything else being equal. So the answer MIGHT be that it won't make a lot of difference either way.

Disclaimer: There are those who believe that being further upstream (closest to the source) increases the importance of the quality of a cable or component. I do not subscribe to that philosophy, my philosophy simply being that a chain is as strong as its weakest link, regardless of where that link is located.

-- Al
I have found the most important cable in my system to be from my phono cart to the phono pre. Likely due to the small signal involved (especially from a LOMC).

But in general +1 to what Al said.
Al, I have read the same as your disclaimer for hours last night, and I tend to agree with you... The weakest link should rear it's ugly head, luckily a Serenade isn't a 25 dollar Monster cable, so although it's not as good as the Crescendo, its only a notch down.

Im just not sure where to place them for best effect. I guess unless someone has some experience with a similar system, and its too subjective at this point, there isn't much to do besides swap them in and out. I also read though that some cables can take time to recover, so A/B/A isnt the best unless I want to let it play for a day or two between sampling. I will eventually get another pair of Crescendos when I can find a deal on them, but until then Id like to maximize what I have invested.
I just went thru swapping cables myself and it was admittedly a royal PITA. However, it did reveal interesting and significant changes depending upon where i placed the ICs and PCs. Source to pre did provide more audible differences. You will have to bite the bullet and try them out yourself. But, i do think you will appreciate the improvements wrought by such experimentation. And thus, be certain that your system is maxed given what you have. Good luck!
After lots of testing, I found that the cable that made the most noticeable difference was the source to preamp cable. So I always use my best cable in that position.
Ok so everyone besides Nismo says either they all matter or do amp to amp first... I guess I will set it up there first and then swap the better cables to the source/pre position and see if there is any difference. I also need to see if digital from the source sounds as good as pre-amp mode with the xlr's. Looks like this weekend my voicecoils are all going to stay warmed up!

Thanks again for all the input, if anyone else wants to chime in with their opinions or experience we all welcome it. :-)
over all good cabling will make a difference. Where to start? The further upstream the more significant the impact (this goes for equipment too). In other words, your source equipment and cabling carries the smallest and most delicate signal - if there is flaws present or introduced here - then said flaws will only be magnified and expanded upon further downstream (preamp, amp & speakers along with the associated cabling). Thus, your best should be source and source cabling. However, due be aware that the absolute best and perfect signal can be ruined by poor reproduction, so downstream is important too. This is the reason you will get so many opinions on such a question - its all a symbiosis...
The way you are going about this is almost a guaranteed fail. I like what Almarg has to say in his post. I will simply add that if you buy cables on recommendations alone and not demo them in your system, you're nuts.
In almost all of my many systems through the years, I have found that the cable from preamp to amp to make the biggest difference.
In my experience, the biggest difference is source to pre . I put my "best" cable there.
Almarg summed it up in excellent fashion.
Xxqq250, I am a little nuts, but I have all Straightwire cables now Rhapsody (about 3 levels from the Crescendo), just RCAs/SWs and I am absolutely happy with them.

I like all my stuff to match, Im not a mix and match type person(too damn complicated). I do the same things in my cars I highly modify, I pick a brand I like and try to stay with all of their products throughout the build, IE Edelbrock etc.