I've spent quite a bit on my AV set up the last few years, I have been careful to avoid higher end Audiophile grade gear as that is a rabbit hole I don’t want to go down! So have stuck to good quality Chinese makes for the audio hardware and I'm happy with my current setup.

50" Sony W8 had about 4 years (not going to bother with 4k yet)

Yamaha Yas-93 soundbar is connected to the TV not the best, I got it cheap in the Black Friday sale a few years ago, its good enough for regular TV viewing.

LG Minibeam PF1000U short throw projector, it its great for Movie night, 100” from 38cm. I had wanted a projector for years but was always put of by the cost of lamp replacements and how they could only last a couple of thousand hours, the one in the LG lasts for up to 30000 hours, its quite low powered so only good for near total dark. I was going to get a screen for it but the wall is freshly plastered and painted in a neutral enough colour that I can correct for it easily using the THX Tuneup app on my tablet.

Connected to the projector is a Q Acoustics Media 4 Soundbar a bit too basey out of the box for my taste but sounds great after fiddling with the EQ a little.
 
SMSL M8A 32Bit/768KHz USB DAC, I have only had this about 3 weeks, I had a Asus Xonar Essence One before that which I had for a couple of years, it developed a problem with not always turning on when I pressed the button so looked to get it fixed or replaced under warranty, I got it from Amazon who didn't have a replacement in stock so offered me a full refund. The SMSL is well regarded at Head-Fi as a entry level reference DAC so decided to take a punt on it, if it wasn't that good I would get a better one and use the SMSL on my Gaming PC. It didn’t sound to great to start off the treble was far to bright but after a week of burning in overnight it settled down and now sounds good so will be keeping it on my HTPC.     

Little Dot MK3 headphone amp fitted with upgraded tube’s, had it about 3 months this is my second Little Dot amp, the first a MK2. It took about 100 hours to burn in very pleased with it once it had. Listening to it back to back with the MK2 the sound is cleaner and a bit more defined, before I bought it I was unsure if it would be a worthwhile upgrade from the MK2, but I'm now more than happy with it.     

Shure SRH1540 headphones, had them nearly 3 years still very happy with them, very comfy for extended ware and good all rounders and sound good with most types of music, I have replaced the cable twice but it only costs 20 quid for a new one.

All are running off my HTPC the specs are:
Silverstone Grandia home theatre case.
Ryzen 3 1200 running at 3.7 GHz, I’m so happy AMD are making CPU’s worth buying again.
Noctua NH-C14.
Asus Prime 350 mobo.
8 Gigs Corsair DDR4 Ram.
Asus GTX 970 totally not needed in this system, but it was spare out of my gaming PC when I upgraded to a 1080, the fan’s don’t spin at all unless under load so perfect for a HTPC.
PCTV Systems DVB-T2 292e HD TV tuner.
Corsair RMX 650watt PSU, has a zero RPM fan mode up to medium power draw, I have never heard it spin up since I got it.
120GB Kingston M.2 boot drive.
3x4TB Western Digital HDD.
Logitech K830 keyboard.

The system is nearly silent the case and cooler fan’s use fan reducers, only time I hear it is when a HD spins up.
 
OS currently running Ubuntu 18.04 with a low latency kernel, I made the switch to Linux full time on my HTPC about 6 months ago, Windows 10 got really annoying when switching audio outputs with the big update they did towards the end of last year, which often could only be fixed with a reboot. JACK audio is superior to Windows WASAPI when configured IMO. Since I got my head round how Linux works I can’t see me going back to Windows anytime soon.

Serious nobody pumps a digital signal through a tube amp it would be gibberish (or speakers/headphones for that matter) that is what a Dac or sound card does turns a digital signal to analogue.  As for accuracy (outside of the recording studio) for 99% of people who listen to music a more soft sound is often better than 100% accuracy. I have quite a large collection of high bitrate 24 and 32 bit audio and some gets quite fatiguing to listen to after as little as 10 minutes at my normal listening volume. The tubes I'm currently using opens up the soundstage, tightens up the bass (makes it more defined) and tone down sibilance and makes the sound a lot more pleasing on the ear.

You should know what I meant, the analogue output from a digital device, such as a CD player. Some companies trying to sell very expensive valve amps claim they are much better, what they really mean is there is a lot of profit for them.

If you know what you have and how to set it up then great, a lot don't even bother trying to find out. Standard around here is a cheap system from somewhere like Currys

Ok  Voskhod with a tube type from 1942  (used ones between 3-4 Euro at radiomuseet) this german moved to sweden with his stuff https://phonobar.se/

Yes Shaun it is a more pleasing sound.   The now run preamps at 9 volt but with a tube ! Some russian tubes are good, like Sovtek.  I am menber of Radiomuseethttp://www.radiomuseet.se/butik/index_ror.html there I can by almoust any old used Tube   Philips, RCA, Telefunken etc. all good tubes. Which kind of tube in your amp ?