Overdriving the Quatafire 610 soundcard preamps ... Is this cool?

Scored a Quatafire off ebay cheap for 80 bucks … always thought if i had to grab a cheap soundcard for some reason, i would always go for that one. borrowed a friend’s in 2007 and it was amazing, the sound - quality and warmth.

Anyway, as usual with digital soundcards i keep it cool on the inputs usually -6db or even lower.

Tonight i am overdriving the input, and it sounds amazing. Like an analog mixer responds when overdriven: favourably.

Is it possible the preamps on this firewire soundcard from ten years ago are analog and that is why it sounds cool to overdrive them?

http://www.esi-audio.com/products/quatafire610/