Thinking about this a bit more seriously, there are some specifications / measurements that are of some use and which are very much of the NVA ethos.
Number of active amplification devices in the pre-amps: 0
Percentage of signal fedback in the pre-amps: 0
For the SA pre-amps, variable resistors used: 0
For the power amps, Input impedance: whatever it is. Plus whatever else it is about the input characateristics that make them more suitable to passive pre-amps than most power amps.
Zobel networks used in the power amps: 0?
Electrical conductivity of cases > 10^15 ohm-cm
Number of op amps used: 0
Transformers in signal path:0
Number of active amplification stages between source and speakers: x for digital, y for vinyl.