raul - Well, raul, you're wrong. The FET stage is used ONLY for MC amplification. Period. The MM stage is all tube. The FET stage just raises the input to the level where the MM section can optimally handle the signal. The different tube complements are used to balance signal level. This information is available directly from Herron himself in conversations with the owners of his products.
The cited post says nothing about any differences between the FET stage and the MM stage except that the listener preferred the sound of his cartridge using the "infinite loading" available on the VTPH-2 MC input. That would be through the FET stage.
Oh, but I momentarily forgot you're always right. And you already said I can't hear anyway.