Simple questions about audio interfaces
 

I am planning on buying an audio interface to record some guitar/bass "dry" and then apply effects/amplification in software like Waves GTR. Not looking for professional quality, just something to create a listenable demo with. :smug:

I have a few questions that I hope you guys can answer. I'm a complete newbie.

1) Some audio interfaces have a 1/4" instrument input jack, others only have an XLR input jack. How do I connect a guitar to an XLR input jack?

2) DI boxes, preamps. Where do these come in and do I really need one? What do they do exactly?

3) Since I am going to use software-amplification, does the input quality really need to be that good? This might be a stupid question but I'm assuming that since the biggest part of the sound is created software-side, that it shouldn't need very high input quality to create decent sound. Is that correct?

4) Is a USB interface best or should I get one that plugs into the mic-input on my laptop?

I appreciate all answers :) Please keep it as simple as possible, tell me only what I need to know.

#3 Garbage in = garbage out

Thanks ddnidd1 for the answer
Can anyone tell me about the other two questions?

If you do a search on this forum, you should be able to find the answers to these common questions. Also try a google search. The information is not a secret.

Some sample links:

http://www.sweetwater.com/shop/compu...ying_guide.php

http://www.platinumaudiolab.com/tuto...udio_interface

http://homerecording.about.com/od/ho..._interface.htm

http://www.m-audio.com/news/en_us-1937.html

Using a DI box. But that wouldn't make any sense since you can and should buy an interface that has a built-in instrument input.
DI box converts high inpedance intrument signal into low impedance mic signal. Needed if the device you're plugging the instument in has no instrument inputs. Again, if your audio interface has an intrument input, you don't need a DI box.

Preamps are a bit different as they usually process the signal in some way, adding some tonal depth, overdrive, compression etc.
No. As said, crap goes in, crap comes out. The input does have to be good to get good results. Luckily it's pretty hard nowadays to run into a $100+ audio interface that would not be at least tolerable quality.
Firewire would be even better for audio interfaces (lower CPU usage, lower latency, more reliable) but if your computer doesn't have a Firewire port, USB would be the second best option. Laptops always have terrible built-in audio when it comes to recording. Usually playback as well. Don't even consider that as an option.

In short, get a $100+ USB audio interface that has built-in instrument input and you shouldn't run into trouble.

Thank you very much atheos, that's a great help! You have answered pretty much everything :) I just had a bit of trouble understanding where a DI box would come in. So, 1/4" input is the ideal, but use a DI box if I only have XLR. Got it!

I appreciate both your answers.

The Focusrite 2i2 has both and two inputs. The 1/4 " is in the center of the XLR. I ended up getting this unit recently when looking and reading many good reviews here at TB.

Wally

Take a look at the ART dual preamplifier with USB. It gives you DI, decent preamps, limiters, can be used with instrument direct in and mic, etc. And you will actually need all of that to get good results, so why not have it, for under $150. I have two of their mono equivalents without the USB and I use them all the time for various things.