Is 1990's equipment vintage?

Who Cares?  unless the question is asked because he has a choice of Only Three categories.
1). Vintage
2). Used
3). New

Look at the item Regardless of Age, the Power Supplies in older will never math the newer, plus the Quality depending on what you have..

I have many much older equipment and will keep repairing should it fail, one example is a Jeff Roland Coherence SS Pre Amp Circa 1997 and Still have trouble finding something equivalent that is not a zillion dollar's..   Just my Opinion is all..  

Who Cares?

Me, I care.  I'd like to ask people what they think of when they think of vintage.  Specifically what the cut off is.  Like, I think 2010 gear is NOT vintage yet.

If I am selling it to you, it is vintage. If you are selling it to me it's old.

In the antique world, generally accepted 50+ years to be vintage.

In the wine world, that is just the year it was made.

For me, most electronics are never vintage, they are just old, except certain turntables, Nakamichi cassette decks and the odds speaker.

You know you're old when you bought new stereo gear in the 90's and now it's considered vintage! In the mid nineties l bought a new VAC PA 100 100 amp and ARC LS 15 pre amp and they are still working fine to this day. Me not so much