I agree with @cellcbern , they sound better than any other new production tube in my LTA ZOTL40 and I even prefer them over my NOS Mullard EL34 FX2. I have never owned a 300B amp so can’t compare but these tubes are the real deal.
Sophia EL34-ST Tubes
Does anyone have experience using Sophia EL34-ST tubes? Currently I'm using GL KT77 tubes in my Primaluna integrated amp. I tried other EL34 tubes along with KT88 and KT120 tubes but feel the KT77 have the smoothest mid-range especially with female vocals without sounding harsh. Supposedly the Sophia tubes have a 300B type sound from one review. Any opinions?