I'm using behringer B-1 mic and a Roland UA101 interface, trying to record vocals.
I'm using the 1st preamp input (with phantom enabled) and although the input is clipped, it's still really really low in the output. Even when I'm using direct monitoring, the knob has to be set almost fully to the direct monitoring side to be heard above the music.
Why is that? it's frustrating...
If I understand correctly, the preamp is turned up to a gain where it is clipping. This means your problem is not with the mic, because it is giving the UA 101 a good signal to work with. The UA 101 is a USB interface, so its input into the DAW you're using is controlled by the software. Check the software settings, because the problem might be that you don't have the DAW input gain turned up, or possible the track monitoring not on.
It would help to know what DAW you work with. I use Reaper, and it's very easy to keep track of levels with it's setup. Turn your monitors down before messing too much with this. You'll still want your hearing when you're done.
Hope this helps.
"to be heard above the music" – above what music? If it's some fully-mastered mixdown that you're replaying at 0dB, then this is no surprise: such a track has lots and lots of compression on it, making it way louder than a clean microphone track can ever possibly be. You may feel that it's the microphone that's too quiet, but in fact "everything else is too loud". What you can do about that – well, turn up the headphones level, make the backing track quieter from the software side (something like -12 dB), correctly set the preamp gain to just-not-clipping, and start recording. That should work out fine.
Note that, for many musical styles, clean solid-state preamps aren't really great for the vocal tracks anyway. Have you ever tried a tube preamp? That allows you to set the gain quite a bit over the limit, resulting in a powerful, driven, yet still warm and pleasant vocal sound. This is also quite helpful to have on the recording headphones, as it gives a very direct, clear and still dynamic feedback to the singer. I also like to put a subtle analogue compressor (something like ratio 2.5:1, threshold -10 dB, soft knee, attack 10 ms, release 150 ms, gain +2 dB) right in the recording chain sometimes. All of this will make the signal a bit louder, without ADC clipping.
But you shouldn't do anything more powerful than this: the downside of all such measures is that you won't be able to alter the effect afterwards, like when you find the vocals should after all have a bit more "open" sound. No hard overdrive or brickwall limiting, please! It really shouldn't be necessary when you don't use too loud backing tracks.
Of course, it's possible that your interface's preamp is simply broken. If the signal is even quieter than a backing track at perhaps -18 dB, then something is wrong. You should check this with your DAW like suggested by Lukas Woltjer.
