Get mics to line level in the field

Question

I'm new to field recording and I have a 744t, but channels 3&4 have to be line in. So if I want 4 mic channels, let's say Rode NT4 on 1&2 and Line Audio CM3 on 3&4, I need to get the 3&4 up to line level before they'll work. Last night I tried just plugging a mic into channel 3 and turning the gain up, but I had to turn it all the way up to barely hear anything.

I know in the studio a mic preamp would do this, but is there anything that would do that out in the field? a preamp or DI box or something? if you could let me know what people use that would be excellent. It seems like the MixPre-D, but what I've read only refers to it as a mixer, and I'm not sure if a bunch of gain on the MixPre-D and then even more gain on the Line level input would just equal a bunch of noise.

Answer 1

Yes, you are correct that inputs 3 & 4 require line-level. You have done your own experiment to show that there is not enough gain to handle microphone-level. Note that Sound Devices gear is pretty much on the top of the heap of audio gear. It has a few peers, but generally regarded that there is none better.

In the same manner the SD MixPre-D is very highly regarded as one of the best in portable, clean microphone preamps. The MixPre-D is both a "mixer" and also good, clean mic preamps. So it is ideally suited as extenal mic preamps for your 744T recorder. Probably most people use the MixPre-D as clean mic preamps to feed into their camcorder (or Zoom shaver-recorder, etc.)

There are probably hundreds (or thousands) of MixPre-D out there being used as mic preamps for extra inputs for the 744T or similar recorders. So you are in excellent company.

Answer 2

Depending on how you want to organise your gear, you can also consider purchasing a couple of Sound Devices MM-1 units which are high-quality battery-operated pre-amps - typically suited to boom-operator belt-buckle useage. Your other issue with using microphones directly into line-input connections is that you are unlikely to be able to supply them with any phantom power. Lucky you could hear anything at all in your case.