Of course as Jeffreybehr points out all low level signal amplification is done with triodes, often the ubiqutous 12AX7, and its clones. The alternative to a triode is the pentode, which is used in power amps that have transformers. The extra grid in the tube is used to apply feedback from the transformer secondary winding so as to correct frequency response deficiencies of the transformer, and, as a secondary purpose, to reduce distortion.
IMHO your shopping list should not be constrained by arbitrary factors like the type of tube. You might not like the sound of triodes.
IMHO your shopping list should not be constrained by arbitrary factors like the type of tube. You might not like the sound of triodes.