Unfortunately, the UA 25EX preamps are not bypassable: no phantom power, TRS cable....but the final result between my Focurite ISA Two preamp and the audio unit is heavily influenced by the latter. A real LINE IN level is not available, because, as AT said, preamps are "autosensing", and also al 0 level with a TDR jack, the preamp still color the sound. This way of construction (not bypassable preamps) is completely insane and it's turning me mad, because I want the clear and natural ISA sound, but the final sound becomes fat and slightly saturated: this is because of the card, I recognize immediately the UA 25EX additive colouration because I have recorded with it for a lot of time! Maybe I have to buy a new interface and for what? Just to obtain a real Line In and use a real preamp as it deserves to be used?! What a good new!!!