Hi Alison,
The truth is, there are a number of factors involved in why you are recieving a low signal but you are correct in assuming that you do need a preamp. Although most preamps do provide phantom power for condenser microphones, that is not their specific purpose. They are simply designed to boost the low level that a professional microphone outputs before it enters a recorded environment. You see, both dynamic and condenser microphones have very low natural outputs, and in many cases, a condenser will have a higher output with phantom power applied. A dynamic mic, on the other hand, is a passive device. It works just like a speaker in reverse. In fact, you could use any speaker as a dynamic microphone if you wired it to a mic jack. So the major reason you are recieving such a low input on your mac is due to the native inability of a microphone to put out a lot of power. Secondly, pro mics and audio equipment have a different standard as far as line inputs go. One is +4 dBV and the other is -10 dBV. It also helps to have a tranformer in line to prevent buzz, however that is not the major problem. You do really need a preamp. Your converter from XLR to 1/8 in is most likely fine the way it is, but you should add a preamp in the path to compensate both for the low output of the mic as well as the baseline line level difference. For most functions you can get a decent pre for under a hundred dollars US. I use this
rolls preamp in my collection and its decent and cheap. However, I would reccommend just getting a simple audio interface with a built in pre. This generally will allow you to record at much higher quality and often includes software to record with. Something like the
M-Audio Fastrack USB will give you a XLR in and 1/4 inch in and will connect with USB. It sells for 129.99 which is not bad considering the price of an individual preamp. Hope this all helps. Good Luck!
Justin S.
