I am looking at non NOS, KT66's or 5881's for a JTM45 RI. Anyone have an idea of how the new production Tung_Sol 5881's would compare tonally and headroom wise to something like GT HP's or Valve Art's KT66's. I'm looking for good tone of course, but would like to keep as much clean headroom as possible, if possible. Not sure what would be the better choice with that criteria to try first. If it matters, the Beano tone is not a factor for me. T.I.A.