Orange VT-1000 Valve Tester

[Crackle]

Orange claims the Testing sequences include:
 Heater filament test: Short circuit
 Heater filament test: Open circuit
 Heater filament test: Tolerance check
 Heater cathode insulation: Leakage
 Heater cathode insulation: Short Circuit
 Tests for heater current abnormalities
 Amplification factor
 Voltage gain
 Power gain
 Screen grid test
 Mutual conductance test
 Dual test for double triodes
 Emission
 Inter electrode leakage
 Inter electrode short circuit
 Flash-over (arc detection, high voltage breakdown)
 Gas ionisation test
In addition to the tests listed above, the VT1000 performs a series of unique tests under varying load conditions which are designed to filter out bad valves and to assess if the valve is good, or needs to be replaced.

I suspect there must be switch mode PSU's involved to get the HT voltage required for testing.
Mike