Greg
Your goals of more warmth, dark sweetness, and euphonic emotional midrange are all characteristics of triode tube amplification. I had a modified (caps, resistors, tubes, and output posts) pentode amp for nearly eight years that came close - but when compared with triode amplification - couldn't get me there! The difference is that now I spend my listening time smiling at the nuances and realism rather than wanting more of this or that. If while you're listening desires for more this or that come to mind - then you are not there.
If you must stick with pentodes - you can mod the ASL for with a pair MIT or Auricap capacitors, some Cardas output posts, and add a pair Siemens EL34s to sweeten it a bit and see if you are closer to that goal of being there. EL34 is as sweet as it gets in pentode land, so if that doesn't do it - it may be time to go triode (the final frontier).
Your goals of more warmth, dark sweetness, and euphonic emotional midrange are all characteristics of triode tube amplification. I had a modified (caps, resistors, tubes, and output posts) pentode amp for nearly eight years that came close - but when compared with triode amplification - couldn't get me there! The difference is that now I spend my listening time smiling at the nuances and realism rather than wanting more of this or that. If while you're listening desires for more this or that come to mind - then you are not there.
If you must stick with pentodes - you can mod the ASL for with a pair MIT or Auricap capacitors, some Cardas output posts, and add a pair Siemens EL34s to sweeten it a bit and see if you are closer to that goal of being there. EL34 is as sweet as it gets in pentode land, so if that doesn't do it - it may be time to go triode (the final frontier).