Not sure if that is all correct.
Here is the specs via Kevin Gilmour:
3000 volts peak to peak stator to stator (+/-750 power supplies)
KG TOGTE
2400 volts peak to peak stator to stator (+/-600 power supplies)
koss esp950
2300 volts peak to peak stator to stator (+/-575 power supplies)
KG’s new Silicon Carbide jfet based space heater.
2000 volts peak to peak stator to stator (+/-500 power supplies)
Stax T2, DIY T2, KGSSHV (ixys parts)
1800 volts peak to peak stator to stator (+/-450 power supplies)
KGSSHV (sanyo parts)
craig has said his new electra amp does 1800 volts, power supply unknown
Ergo Jecklin
1600 volts peak to peak stator to stator (+/-400 power supplies)
BH, BHSE, singlepower ES1,ESX (after being modified to remove the 100V offset)
Cavalli Audio Liquid Lightning
1400 volts peak to peak stator to stator (+/-350 power supplies)
KGSS,Stax T1,T1s,T1W,313,323,717,727,sra-14s,srm-1 mk2,srm-monitor
woo audio wes
1300 volts peak to peak stator to stator
stax sra-10s/12s
1200 volts peak to peak (+/-300 power supplies, and +600 capacitively coupled)
KG tube #1,aristaeus,HEV70,HEV90,RSA A10,srm300,Exstata
Egmont,Cirolan,SRM-1,srm-3,woo audio ges,srm310
1100 volts peak to peak stator to stator
stax sra-3s
stax srm-001 (when the batterys are at full power)
1000 volts peak to peak (+/-260 volt power supplies)
Rudistor Egmont
960 volts peak to peak stator to stator
Stax srmXh, srm212
540 volts peak to peak stator to stator
Very early HEV70 (+525 volt power supply and tubes biased at 390 volts)
I can say categorically the Stax 727/717 is way behind my KGSShv, I know I had the 717 at the same time on my 007As and the 009s. It is also not just the specs or voltage, the design of the power supply and the output is key here. The 717 sounds thin, strained and flat with a constricted soundstage and a cold unnatural treble. So listening is the key here, the specs try to say they are close which is afar from the truth.