I wouldn't think the differences in timbre & tone would be subtle, but color me confused. Your system sounds top-notch - just the kind of gear I like - and I'm sure you can hear.
I would certainly try replacing all the tubes. In fact my DAC is probably due for a new set too. Good thing they're all cheap.
I would certainly try replacing all the tubes. In fact my DAC is probably due for a new set too. Good thing they're all cheap.