Secondly, before I have had troubles with the whole volume of my recordings. Would it be wise to buy a pre-amp, along with a mixer because I want one, to get better volume levels?
I assume you're refering to the volume level of your finished mixes, and you're comparing them to commercial releases?
If so, the problem does not lay with the pre-amp, but rather the "mastering" of the track. I would research into mastering and how to use a limiter on your stereo buss (where all the tracks get summed) to increase the average level (RMS in technical terms) of your recordings. You can try playing around with this in PT by creating a Master (found in the same pull-down menu as creating a new audio track) and using PT's limiter - you'll notice the more you compress, the louder you can get the track, but the worse it will sound *in broad terms*.
In terms of tracking volume, you should be looking at having your tracks peaking around -16dBFS. To check this, use PT's own (free) spectoral tool, which will give you a peak level reading.
I've been looking at the 003 Rack and wondering if this would be a good upgrade from the mbox if I want to get more serious recordings done..
THe 003r will allow a number of things:
1) More simultaneous inputs and outpus (a total of 18 i/o can be accessed whereas the Mbox Mini only has 2 i/o)
2) More preamps (003r has 4, 003r+ has 8)
3) Recording/mixing up to 96kHz sample frequency.
4) Supposidly, the preamps in the 003r should be better than in your Mbox Mini. YMMV.
So, if you plan on recording more sources simultaneously than you currently are, or wish to access higher sampling rates, then it could be a worthwhile addition. However, this will not help you fix your first problem.
Makes sense. It would be my Yamaha compass acoustic thru an MXL 67i into the mbox mini.
There's nothing wrong with that chain - if you're looking for a better sound quality, then you could skip the Mini's preamps and buy your own stand alone preamp. Again - this won't solve the volume issue that you've raised.