Best upgradable system components for under $6K

"You might consider active speakers since at least one of the components (the amp) comes along for the ride.
Bob_reynolds (System | Threads | Answers | This Thread)"

Going with active speakers would almost certainly be a huge downgrade in sound quality. There's just no way around it. The OP is considering a Ayre/Vandersteen combo. What kind of amp in a powered speaker would be the equal of an Ayre V-5? No active speaker that I know of, at any price, has an amp that can even comes close to it. When you ask the question, who is the best designer of solid state amps and preamps Charles Hanson is going to be at the very top of the list. There's only a small handful of designers in the world that are in his league. Now look at the speaker. What active speaker is on par with a pair of Trio's? Again, there isn't one. Like Hanson with Ayre, Vandersteen is one of the worlds best speaker designers. Vandersteen speakers are all time and phase correct. Its not easy to design a speaker that way and I'm pretty sure there's only 2 companies left that build speakers this way. Vandersteen and Green Mountain Audio. Thiel died and the company is no longer making speakers and Meadowlark went out of business a few years back. You really can't substitute a Vandersteen with any other speaker. Powered speakers are going to come up way short in comparison to what the OP is considering.

I wouldn't be dismissive of every active speaker. As with all audio products there is a hierarchy and a spectrum that exists. A trusted audiogon member purchase the Avantgarde Zero active system several months ago and says it's really quite special. Based on prior experience with him I have regard for his opinion and sonic impressions. Of course you'd have to hear it for yourself, but that applies to everything audio.Is it better than Vandy and Ayre? who knows, you'd have to listen and decide.

A well designed active system will out perform an equivalent passive system every time. Actives allow for better implementation of crossovers and improved synergy between the amp and the crossover/drivers. Examples are JBL, ATC, Pass and Gradient.

To your question about the Moon amps, they're made by Simaudio in Canada and are great products, impeccable build quality, ergonomics and sound.

I've owned three of their integrateds and two DACs and they've been among the most satisfying pieces I've had in 40-something years of swapping out audio gear.