[vdubreeze]

Ah. Well, it's harder to record a nylon string guitar with certain goals. It puts out less volume when picked gently and if you strum hard it self compresses, so that it just doesn't put out a lot of volume. It's a tricky one : ) You're coming up against the issues that everyone does with this. The only real solution, as far as excess noise in the signal path, is having really good signal to noise ratios in as much of the gear in the chain as you can. IOW, the Samson and Audiobox are both not great at such low levels. They have noticeable self noise if there sound captured is low. The mic will simply be set at what it's giving, and if the Audiobox is turned past a certain point, maybe past 3/4, it starts adding more noise and not giving much more source signal with it. Short of getting ahold of a hotter output and lower self noise mic and a cleaner interface, there are two things you can try:

One is to simply record lower. Position the mic so that it gets the best sound, and don't turn the input on the interface up to where it starts getting noisy. Then raise the level in Reaper, if you even have to. It won't be gain staging the same noise because (probably : ) ) the interface literally is adding noise up there, and turned down will be quieter even when brought back up in Reaper. Another thing is to get a mic level booster, like a Triton FetHead, which will give a clean gain boost of 20 - 25 db. (Have to use the right one for the mic. Dynamic and condensers get different models.) They're often used for lower output mics and work great. Whether the Samson boosted up results in what you need is hard to say, but the idea is that you can run your mic pre at half what it was because it's getting a much stronger level to it. Even a great sounding expensive mic that is low output might sound crummy into an inexpensive interface with the gain turn up to max, and might sound good with an inline booster and the gain reduced.

But try just recording hitting Reaper lower and raising it and see what happens : )