When you want to improve your system, it is hard to decide what to invest in. This is my experience. I have a large room with high ceilings, and with the digital side of my system, I was hearing some harshness in my system at high volume, which was causing fatigue. As a modest income guy, that mostly buys used equipment that I could not afford new, I was not too motivated to change out my components... I was primarily focusing on changing my DAC, thinking I had to go RTR. In the end, I decided to focus on where I had skimped before changing components. First, I moved my speakers farther apart and changed the toe in. Then, I upgraded all my interconnects, speaker cables, power cables, added footers, changed all my worn reissue preamp & amps "small" tubes to high quality vintage tubes, and added an audiophile grade rack. Viola ! that fixed it. What a huge difference ! Everyone noticed the difference, and I can now play at any volume without fatigue. So, the lesson I learned is that an expensive DAC will probably improve your sound, but, may not fix what you are trying to fix if you have weaknesses elsewhere...
PS.. although now, I would like to hear what a higher quality DAC will do for me. lol...