My Dennis Had Firebottle HO (it's a HO...says right there...) is a single ended pentode amp at about 12 to 17 watts (HO is "High Output") depending on tubes. Although Atmasphere's frequent comments regarding SET (Or SEP in my case) distortion make sense, after using various tube and SS amps over decades, my Firebottle never sounds harsh or distorted or anything besides beautiful through high efficiency speakers with all sorts of music at any level I can tolerate. That said, Gold Lion reissue KT77s seem to stick around in this amp longer than KT120s, 150s, 7581As, KT88s (GL or Sovtek), or anything else now living in my crowded tube drawer.
Pentode Power Tubes - Ultralinear vs Triode
While I’ve seen a bunch of posts on power tube rolling, I haven’t seen much mention of how preferences correlate to what mode you run if your amp has that option. I have a Primaluna DPHP that has the Ultralinear/Triode mode remote and can run a bunch of EL34 variants up to KT150.
So far I’ve only tried the stock EL34 and Tung-Sol 7581A and seem to prefer Triode mode with both. Before coughing up for another set of 8 to try I’m doing more research. I think based on my preferences so far that the bigger, punchier tubes may not be the way for me to go. I could be destined to find my way into SET amps eventually.
So which tubes do you prefer in what mode of operation?
So far I’ve only tried the stock EL34 and Tung-Sol 7581A and seem to prefer Triode mode with both. Before coughing up for another set of 8 to try I’m doing more research. I think based on my preferences so far that the bigger, punchier tubes may not be the way for me to go. I could be destined to find my way into SET amps eventually.
So which tubes do you prefer in what mode of operation?