Beginner looking for guidance into tube sound.

I would consider a Jolida 1501BRC, it is an integrated and has 12AX7 input stage. They are pretty damn reliable and sound good. You should be able to find one used for around $600ish. Read some reviews but only get the BRC version its the best one. Good luck!

If it is so important to add some "tube sound" then yes a preamp is more in your budget. In the longer run however I would never do it, not on your budget, because separates are so much more costly for what you get. My budget for example is a lot more and even at my level I still do not see the advantage of separates. 

I just went through this myself and went with the Willsenton r8. It’s around $1300 and will 100% give you the full tube experience.

Don’t listen to that crap about needing to spend 2k+ minimum or even that tubes are expensive or difficult to maintain. The Muzishare and Willsenton are excellent amps and easy to live with. I takes about 3-5 minutes to bias my amp and is a complete non-issue unless you tube roll the power tubes. This would be very unusual (tube rolling is predominately for pre-amp tubes which don’t require a bias adjustment). And even if I was to roll power tubes, its kinda fun to bias, makes it seem like more of a hobby.

Power tubes last around 2500 hours or so and there are plenty of new production EL34 and KT88’s that sound excellent for around 25-50 per tube. The new issue stuff is also getting better and better. I listen to music about 10hrs a week at most so even w KT88’s at $50 per that’s $200 every 5 years.

Pre-amp tubes last twice as long and are less expensive unless you want some rare NOS tubes. If you are on a budget though, you can get NOS Russian Federation 6sn7 & 6sl7’s from the 80’s for about $5-10 a tube that actually sound great. That’s also what Willsenton ships with the R8. I have yet to figure out who makes their stock power tubes, mine had no markings.

If you would prefer keeping the Nova 300 in the system, then go with the Schiit Freya+ (without tubes $850, and get those Russian 6sn7’s as a starter set) or a used Freya (about $650). This is what I plan to do. I still have a SimAudio W3 that I own, and I’m going to try a tube pre to see how much of the "tube sound" I can get from the pre-section. I plan on keeping the R8 no matter what. Hopefully I can get some of the lifelike sparkle and 3D holographic thing tubes provide that transistors alone seem to miss.

I recently bought a Cronus Magnum that was within your budget. Sounds wonderful and drives Maggies with ease. The only downside is that it's a space heater.

Hey,
I haven’t read through the entire thread but if it hasn’t already been said you really need to listen to a tube  based system before you make any choices. With respect to others I think that you can find good tube equipment in your price range. I especially like the idea of building your own equipment. Sadly the audiophile hobby is IMHO overloaded with hyperbole. I’m not trying to rake the forum or to suggest tubes are better than solid state. I’m saying system synergy is key to musical bliss. Finding a system that creates that for you is challenging and that is where a lot of money is spent usually with good intentions but the end result is are you satisfied with what you are hearing? Chasing that down by reading reviews is impossible. Before you spend any money find a way to listen to several types of gear. That’s a difficult task to be sure but is the only way to make a choice that not only fits your budget but achieves the sound you crave. Keep in mind too when and where you listen really affects what you hear. Bottom line, listen to a tube based preamp and monoblocks with perhaps an analogue or digital front end an entire system. Something that gets your attention, something that is clearly better to you. Something that turns your head and sits you down, where you forget about the gear and just enjoy the music in a way that brings all details to life. It can be a very enjoyable endeavor and quite costly. But I believe it can also be done on a budget if your goals are reasonable. Go out and find some gear to listen to, ask a bunch of questions no matter how smart or embarrassing they may seem, then decide. Best of luck