As compared to current production EL-34's the Svetlana can take som major punishment and still last for month's without failing. This tube can take the full 25 watt plate dissipation and keep playing for month's. I recommend this as a good all around EL-34. My only complaint with Svetlana EL-34's and 6L6GC is the variability in the size of the glass envelope coupled to some irregularities in their physical construction.