In todays post we look at a simple low cost hack, that will allow you to use XLR mics with your DSLR camera. Giving you great quality and control, without the need to buy an expensive preamp or sound recorder.
For my smartphone journalism work I really like using the Røde Lavalier mic, so I thought I would try it out with my DSLRs. Unfortunately the mic requires phantom power, which is a feature that my simple DS214 Juiced link preamp doesn’t offer. No problem I thought, I also have a the more sophisticated Tascam D70, but unfortunately this doesn’t work with my Panasonic GH2, because it only accepts mic level inputs! Not wanting to have to invest in another expensive preamp, I did some research on the net.
One solution I found, was to use an IK MultiMedia iRig Pre. This is a low cost (£29) analogue preamp, used for connecting XLR microphones to smartphones. I have written about it before and was very impressed with the quality. It has the advantage of having an XLR connector, manual gain control and providing phantom power. Full details are available here.
The problem with the iRig Pre is that it outputs to a 3.5mm TRRS plug, which works great with phones, but not with DSLR cameras. The easy way to test the concept is to use simple headphones/mic splitter. Having tried it I was really impressed with the sound quality, but less impressed with the spaghetti of wires. So I followed the instructions on this YouTube video to remove them. The instructions are great, but you will notice in the comments that there is some confusion about which black wire to remove. So I thought I would document the process, to make it clearer for anyone else following the procedure:
The hack removes the TRRS output wire and allows you to connect the preamp directly to your camera using the redundant headphones jack, via a 3.5mm/3.5mm stereo cable. If you know how to solder, it is an easy modification that takes less than 10 minutes.
3. Now cut off the cable at the position shown. If you want to make a really neat job you can remove the circuit board from the case and work on the back side, but the easy option is to leave it where it is.
4. The next job is to remove the green and black wires (There are two black wires, you want to remove the one towards the XLR plug, NOT the one next to the headphones jack). Just cut them off flush with the board or wriggle them till they break.
4. You should now have three wires remaining. Yellow/Red/Black. Simply cut these shorter and solder them together. Put a piece of tape around the joint so it doesn’t short and the job is done. Assemble the unit and you now have a preamp, that you can connect to your camera using a simple 3.5mm to 3.5mm stereo jack.
Set your camera input to low and use the adjustable gain controller on the iRig preamp to set your levels. The Preamp is much better quality than the one in your camera, so you will get a clearer signal, with less noise. If your camera has a headphones out, you can use this as usual, to monitor your sound.
There is a good video here by Mike Kobal, showing the iRig working with a Panasonic GH4