I have no issues with SETs.
One has to ask how much they care about distortions figures that are less than 1% and how important the memory distortion is...
If that is your cup of tea, enjoy it. I kinda wanted to keep this string on capacitors if possible. Maybe start a new string?
And 1% at what watt output? Most competently designed PP amp will have less distortion than any dht amp for a given wattage output, and better frequency response. Below are distortion figures for a 300b. Please note, the distortion only becomes very low with very low wattage output. Of course, one could add negative feedback to lower it. Many do with PP designs and OTL designs as well. One must also addressed the high distortion of the driver/input tubes.
The top link graph is the intermodulation products of a 3/2 tube characteristic curve (IMD).
(Courtesy Eimac.) Notice the 3rd, 5th and 7th orders. Just above the 300b distortion graph.
-20db means approximately 10% distortion, -40db equates to 1%.
Other tubes such a 45s and 2A3s have so little power output for same high distortion figures. High power 845s etc
also have problems with power supplies and high driver/signal stage distortions due to low Mu of 845, which creates multiople stage higher order harmonics.
cheers
steve