Vintage DACs. Do they hold up over time?

I'm talking about Dacs from the 90s that were well regarded like the Timbre tt-1, Sonic Frontiers SFD2-MkII, Threshold DAC 2,
Wadia 25, Altis Reference, Levinson 36, Meridian 566-20, EAD9000,
Kora Hermes tube dac etc.