I once owned a Vincent SV-226 and thought it to be a very good integrated. Authoritative bass, smooth articulate mids and treble. Wish I had never sold it. I have not heard the SV-500.
If needing a phonostage and your Vincent plays well with your speakers I would keep it and spend on the phonostage. Likely would get a greater system upgrade than swapping amps.
If needing a phonostage and your Vincent plays well with your speakers I would keep it and spend on the phonostage. Likely would get a greater system upgrade than swapping amps.