Rig building - When or Why, do you change devices?

My buying and selling is pretty much exactly as posted by Tvad above. I have found that sometimes an upgrade of one component requires changing another to maintain synergy, sort of an endless loop.

One thing I have learned over the years it is that component matching is very important and unpredictable. I have had many systems but finally decided to let the pros do it for me and now have mostly Audio Note gear which is a delightful complete system. Upgrades are still unpredictable, but always an upgrade, which was not always the case in the past....

I always like what I have and I'm always looking for something I will like better. Finances, family considerations and experience have all conspired to mitigate my restless tendencies over time. And I've learned that I really don't care all that much about the results...I just like screwing around with it as a pastime. I don't think I've had anything that sounds bad since I moved beyond my Bose 901s in 1978.

I found that once you upgrade one component to be sonically better, the rest of the component in the chain then needs to be upgraded as well to a similar level.

I upgraded my cdp and that resulted in wholesale change of all my other components. I guess the phrase your sytem is only as good as the weakest link plays a part in my willingness to swap out gear

I expect that there is a considerable psychological bias to liking the "new" thing more than the old. Just by entertaining the idea of trying the new thing probably leaves us with a predisposition towards the new one. How do we know that we want to try the new thing? Someone, somewhere, said something or wrote something about it, or about its predecessor, or about something similar. Or it looks cool. Otherwise, there is no way that the thought would enter our heads.

I think Macrojack is right. A lot of us are twiddling and tweaking and changing because it is interesting to do so. I have read many posts out there where the writer has seen evolutionary changes through a half dozen components (the same role; e.g. CDP) and while I have listened to many more than that, and there are incremental differences between a lot of CDPs, there is more to do with system synergy and that day's predisposition than there really is with the components I bet. Since I bought my first high-end system, very few times have I found something with which I could not live happily.

Personally, I wait for great things from the past to come around at a stupidly cheap price, then pounce. Because if it turns out to be all hype, someone else is probably out there doing the same thing and I won't lose much on the turn...