Palasr is correct on all points.
I would only add that perhaps the bigger issue is whether to bother with (i.e., pay for) tubes that are "low-noise" in the context of preamps. While it obviously depends upon the preamp, my experience is that low noise is not a necessity for line stages, but that for phono stages, it is very important.
I would only add that perhaps the bigger issue is whether to bother with (i.e., pay for) tubes that are "low-noise" in the context of preamps. While it obviously depends upon the preamp, my experience is that low noise is not a necessity for line stages, but that for phono stages, it is very important.