Do I need a DI if I have a condenser mic? Or should the mics pick up the guitar well enough so that I don't have to turn the input levels all the way up?

    


input levels are a different issue.


no matter what the source, you always want to achieve input levels with the same goal in mind:
a great capture.


you don't want 'overs', but you also don't want a weak signal that might raise your noise floor....


you should always set INPUT LEVELS for their OPTIMUM SETTINGS
\




what is that setting you ask?


well, that's the name of the game, really....
getting to know your equipment, where 'OPTIMUM' really is, and figuring out how each element of the recording chain works GAIN STAGING wise.




after that, it's all about the source, and the TECHNIQUES for capturing the source.


if the guitarist LIKES the sound of the pickup in his guitar, then use it...
but also add in a decent microphone (the choices are huge) and blend them together, favoring the mic over the direct sound.


even the way you blend these together, is a critical element in making the guitar sound... perfect.
you gotta experiment, but look at the basics first.

a good mic will almost always sound better than a DI, in my opinion and experience...

you also need to pair a good mic, with a good mic preamp.

you don't have to spend a mint..

but if you don't at least start with decent gear, there is a price point where you just don't gain anything.
and the low end stuff, is never going to sound as good as the higher level stuff, it just wont.

anytime you get into a pissing contest over gear, all it takes is an afternoon at the local pro studio, listening to their gear, watching them set their levels, listening thru their monitors, and you'll know the truth.

I have had nice results with this combination (Recordings of my Alvarez acoustic / with built in pickup). Condenser mic at or around the 12th fret --- kind of close up - around 6-8 inches) which is my preference and aimed somewhat away from the sound hole. This goes to one R input of my interface and a mono DAW channel. At the same time, a direct line out to a Fishman Acoustic Aura-16 (a very sweet piece of equipment) set to the guitar/mic emulation of choice- to the R input, and second DAW channel. These are recorded together, then panned L and R, with some corresponding EQ to emphasize the highs and lows from the viewpoint of a listener. I play a lot of fingerpicked chords,  mixed with strums (some muted), so this set up ends up sounding nice. Then I overdub this with just the mic (same position) much higher up on the fretboard with a capo; some intermittent lead or fingerpciking. This is usually panned a little to the right to sort of stand on its own - with volume automation to keep it just under the main guitar - occassionally coming up to fill a space. Vocal is then put down the middle of all this....

I just checked out the manual for your Octa-Capture.  If you're using a condenser mic you will have to turn on the phantom power...see page 36