How many years is a flagship component good for?

Possibly forever...

There really isn't anything new in pre amps. Don't fall for hype!

I buy my gear by purchasing top end units from the past. I am just considering bringing my speakers up to 1996 from 1983. Despite their age I have heard VERY FEW that equal my present ones. I often use a tube pre built in 1987 and SS amps from the early 90s. In fact with minor exceptions everything in my system has been discontinued and was so when I bought it. I regard it as a total myth that there has been an across the board upgrade in digital as well; in fact the opposite is true in most cases. One of my DACs is the Audio Synthesis DAX from 1992, its current rating on the HIGHFICRITIC scale is 46; a current MSB that runs about $10K is 48 and many current 2 to 4 thousand $ ones are in the 20s. The Benchmark is about 25. I use a Meridian 200 transport from the early 90s as well. GOOD components age very well, the trick is knowing the difference between good and expensive, they are not necessarily the same. Current best equipment will be better than past best equipment but the cost is usually totally disproportionate. Those who MUST have the latest and the best subsides the rest of us. But even in the latest equipment there are relative bargains to be had; I see current top equipment listed here at big savings all the time; just not as cheap as really good discontinued ones.

15 minutes, as the hi end business model call for better to be available right after you purchase it. Among my antiques is a forth year old Kenwood solid state unit that puts some of the current solid state stuff to shame. You figure.

Until the new flagship comes out - unless deemed an audio classic by desireablity of the educated masses then until it is surpassed by better technology.

odds are a 15K preamp then would be like a 25K preamp now. (both are way too much for any preamp, imho)