Don't most audio interfaces have preamps already?

No, not really.

Wouldn't you be stacking preamps?

If you bought a dedicated preamp and an ADC with pre's, Yes.

I heard that doing that creates extra noise.

Ehh... Not really creating extra noise, really more like wasting your time, money, and not using gear appropriately.

You gotta meet your own demand.

Meaning: If you have a dedicated pre, you dont need an ADC that also includes pre's - for instance, say you have 24 dedicated pre's. You'd want something along the lines of a MOTU 24 I/O, as opposed to 3 Presonus Firestudios.

I have a post here somewhere that explains that a little better, give me a sec to find it...

Ahh I see, thanks for confirming :)

bent wrote: A preamp and an ADC are two different things that often end up in the same box.

Gear like the Firepod, M-Audio Fastrack, and Digi003 are preamp / ADC combos.

Units like the Digi888, Apogee AD8000, and MOTU24I/O are purely A/D converters.

Others, like the Earthworks 1022, Groovetubes Vipre, and the Focusrite 428 are dedicated preamps.

There are many, many more models and many different variations...

Found it!
:lol:

Quick question(s) that's sort of related (to preamp confusion) ...

A preamp with an XLR and line in ...

If it's connected in series, does that mean both connections are connected to the pre? And if it's connected in parallel, does that mean they are not?

Or is it the other way around?

The line in is meant for an external pre of your choice, yes?

Methinks you're thinking too hard about it. The line in is meant for line level sources (keyboards, direct signals from guitar, bass, direct box, etc). The XLR is meant for microphones.

Microphone signals have lower impedence than line level signals, so use a slightly different input stage.