I think the source is very important. Some say the most important. But, I think it's really the synergy among all of them that count. If you have low efficiency, either big floorstanding speakers, or low ohm bookshelves, you are going to need some power. My personal choice is a big solid state amp, high current, high power. This type of amp will lower the noise floor as it will not have to overwork to drive the speakers.
I think tube amps sound fine or more efficient 8 ohm or higher speakers. I had a pair of Rogers LS 3/5A 15 ohm speakers that were phenomenal sounding with a vintage tube integrated (15 wpc) for near field listening. There are a lot of nice tube amplifiers out there when paired with the right speakers and preamp will give you audio bliss.
With my big Polks I prefer a nice tube preamp and a solid state amplifier that has plenty of current and power. The tube preamplifier will take some of the edge off the digital source, maybe with a little colorization depending on the tube. I have a tube phono preamp that sounds wonderful with the tube preamplifier.
Digital or vinyl, it's all good and it is just part of this hobby that makes it interesting. What matters most is how it all sound to your ears. I humbly offer some of my listening experiences and preferences given my room size, acoustics, and listening levels.
Don't be afraid to experiment, always try to get a piece of equipment that you can use in your system before pulling the trigger to buy.
