Re: How would you define a Vintage sound?
I would describe it as the sound of a lute or a chamber orchestra playing J S Bach and similar.
In guitar terms, it would be early acoustic music from centuries gone by.
In terms of what i suspect you're really asking .... No master volume controls, no pedals, curly guitar cables, lots of low-power speakers and amps running wide open. Big, bold, dynamic sound.
In a concession to modernism, a booster pedal (treble boosters included) and a wah-wah pedal. Possibly even a tube tape echo unit.
But to me, what is considered vintage sound is simply normal. I have heard that tubes will one day be replaced by some device called a transistor, but believe me, that will never happen. Radios and calculators that can be carried in the pocket? Pfft! Dream on ! The next thing will be people trying to tell me a computer won't take up three rooms in my house. You crazy young people today.