Some components too old now?

I’m still using a 1964 Sansui 1000a tube receiver with a modern dac and newer speakers. Sounds great. Just had it completed rebuilt. Should be good for another 20 yrs.. The worst thing is purchasing the 7591a power tubes which are expensive. I agree with other members and would look into a nice dac. 

It not that costly to upgrade your components.  Amps usually have large capacitors with two leads on the top.  You can just match the values and swap them out  just measure the new caps and the clamps prior to ordering them.  Nichicon you can buy at Parts Connexoin in Canada, etc.

Just saying

1984 Klipschorns, NAD 1600, Mc 275, Mcd 707 the Node 2i is the only thing new. Happy with all of it, solid old equipment beats the snot out of a lot of the expensive new stuff. There was much greater sales volume of HEA in the 70s and 80s, more volume = better profits = better r&d. Imo those solid old components can't be beat.  I listened to a set of speakers the other day that darn near made my ears bleed, they cost as much as a house and had diamond tweeters, and sounded awful.  Certain things just work, tubes,horns, solid engineering. 

Of all the things mentioned I would say the DAC is the main piece I would upgrade and the CD player last. That or a an updated mid to high end CD player with a better built in DAC than something from 1990. 

Thanks for all your comments. Boiling it all down, it seems that the only thing I should consider is potentially changing my Aragon DAC.
Does anyone know much about the Aragon D2A? It has a separate power supply, and I remember that in its day it was considered one of the best.