Can someone who really knows tell me if there is actually a 2 watts difference of maximum plate dissipation between these two tubes? Speaking strictly RCA here. (Not GE, TungSol, etc...) Some say the GT is rated at 12 watts max and the GTA is rated at 14 watts max. However from what I can find online from the old RCA spec sheets, the only difference is the controlled warm-up time and all other parameters are the same. Am I correct?