Mind explaining that last part? Im having trouble wrapping my head around it. Are you saying that 45s have the best resolution but are soft? Or are you saying all those tubes (300b, 2a3, el34, and 45) are all soft?
Yah. I think thats the easiest route. Tons of good tubes that will run DTC just fine but you do have to be a bit choosey.
just personally, if you dont use speakers, I would lean more twoards getting a headphone amp with a good pre as opposed to a dedicated pre. Just gives you a lot more versatility tbh, and I don't think finding pure tubes for DTC is all that hard in the first place. Im more than happy to give some reqs if you let us know your budget. Just on a personal level, I think the kind of 2-3.5k used range would be where I would put the general sweet spot for DTC price/performance. Below that range and vintage preamps may be a better bet overall.