Some components too old now?

I’m using an optical connection between the CD and Aragon DAC. I must have discovered long ago that this gave me the best sound. Is USB any better...?

PS I don’t think I’ll ever use streaming or HDD so that’s not a consideration. I’m primarily vinyl, and CDs are so cheap these days second hand.

Miss my Sentec Diana DAC, looked for it for over a year, used it to my Quads -63 (still in the wardrobe), must be somewhere...

@vinyloid,
Yes, I got the same take on those thread. So, maybe I'm wrong. The only way to tell is try and audition some more contemporary DAC's. Though I have to say DAC's from the 90's never contemplated the high resolution being offered today.
Re USB, a touchy subject...
For me, I loathe USB. Way too twitchy and dependent upon all the equipment around it. Just look at all the products offered to help clean up the USB signal.
I prefer optical. You just can't pinch it -(like Verizon did. It took 9 months for a tech to find the problem of my services dropping erratically).
Bob

I had my my Classe Audio preamp and amplifer since 1990 and only changed as I blew up the amplifier trying to adjust DC offset on amplifier.   My Magnalab tuner has been going on 30 years.    If you are happy with the sound no reason to change out.   I do agree that digital has come a long way particularly in handling jitter.   A reasonably priced DAC may be in order.   

If money is constrained I would highly recommend yo listen to Schiit.

That's the problem. The Schiit is plentiful. We need upgrades! :)

I have to applaud the music loving OP and a couple of other posters for getting a system you love and just...*loving it* for 20 & 30 years. It screams 'mentally stable'.
I know I'm not alone when I say there have been about a dozen amps in my life during that span. And PREAMPS. Christ, I can't even remember more than a handful of 'em.
Another option for the OP, if you love your stuff that much, perhaps you might think about 'modding' your pieces with some, if not all, of the caps replaced. Look at it like preventive maintenance, and it is. Old is magnificent, but caps do dry out.

So you can try out a Schiit Bitfrost MB directly from Schiit. If you don't hear a moving difference, bounce it back. They take returns.
And the mods, you can spend anywhere from a couple of hundred to a serious $600 or so. Depends on who, what, where.