VTL amplifier Tube brand

Does anyone know what brand of current production tubes VTL is shipping new units with KT88 or 6550 power tubes in their amps as of late?  Time to think about replacement as I’m coming up on 2200 hrs or so and want to get these ready to switch over for my fall/winter amps.  Too hot to run the siegfrieds in Arizona in the summer.....AC in that room never shuts off...Thanks all!