i have owned the totem forest for 4 years and now stiil using it in my system, in the past i had tried them with tube amp with 40w and the sound is terrible, then switch back to 120w ss amp which i currently using. my guess is that because the forest sensitivity is quite low 87db and consider not a good match with low power tube amp, if you want to go with tube try one with at least 100w
good luck