sean mclennan wrote:So the input doesn't HAVE to be balanced then?
No - it does not. If your cable run is only very short, and you have a microphone mounted to the camera, the benefits of using a balanced cable would be minimal if not non-existent.
Brad Ballew wrote:So I guess my question is this: is there really a need to add a converter that would convert my signal from balanced to unbalanced if I am only going to have my mic on top of my camera with just a few inches of cable connecting the two?
In terms of balanced vs unbalanced - no, you do
not need any additional hardware. In your case the microphone itself is unbalanced, so you will achieve no better quality "converting" it to balanced before sending the signal to the camera.
Again, the only benefit of balanced is noise removal as explained in the video I linked to. Technically, all that's happening is you're sending the same audio signal down two cables (instead of one), with one of those signals "inverted", and then simple maths is used to deduct any noise picked up along the cable run. There's no magic involved - you're basically just using maths to remove any noise floor introduced into the cable.
Putting the balanced vs unbalanced issue aside for a moment - I'd still STRONGLY recommend using an external pre-amp/mixer (such as a juicedLink BMC366 Low-Noise Preamp or Sound Devices MixPre-D). This will ensure your connection from the camera to the mixer is balanced, and give you much better pre-amps (as the internal pre-amps in the camera are pretty cheap and nasty).
However, going back to the balanced vs unbalanced discussion, here are some common situations (hint: when I say "JACK" I'm referring to a 1/4inch (6.35mm) phone plug - such as is found on the side of your Blackmagic Camera. When I say device, I mean microphone or other input):
- If you have an UNBALANCED MONO device then you need to use a MONO JACK (i.e. a one black band - tip and sleeve) to go into the camera.
- If you have an UNBALANCED STEREO device then you need to split the signal into TWO MONO JACKS (i.e. a one black band - tip and sleeve) and go into the two inputs in the camera.
- If you have a BALANCED MONO device (i.e. a microphone with an XLR), then you need to use a STEREO JACK (i.e. two black bands - tip, ring, sleeve) to go into the camera.
- If you have a BALANCED STEREO device then you need to split the signal into TWO STEREO JACKS (i.e. two black bands - tip, ring, sleeve) to go into the camera.
- If you have an UNBALANCED device that's only a very short distance away from the camera, then just connect it directly to the camera.
- If you have an UNBALANCED LINE LEVEL device (such as a Rode Video Mic) that's FAR AWAY from the camera (i.e. you have a Rode Video Mic on a boom pole), then the cheapest solution is to use a DI unit, DI box, direct box, or simply DI (variously claimed to stand for direct input, direct injection or direct interface) to connect your high-impedance, line level, unbalanced output signal to a low-impedance microphone level balanced input, usually via XLR connector.
Hope this helps!