I know the 3 tubes have different characteristics so lets not even get into that side of the discussion. My question is if you are running two similar 20 watt amps, one equipped with 84's and the othe with 34's or 6L6's, if you are not pushing the pwr section can you really tell the difference in tubes since the pre tubes are doing the majority of the work? I play loud enough to "feel" it and no louder than that. So at the volume i play i dont even know if the power tubes would even have a chance to add their "character' into the overall sound.