How to Connect an External Microphone to a Canon Camcorder

I recently got a Canon Vixia camcorder.  I got it partly because I have used Canon Powershot cameras for years and liked them, and also because it has an external microphone jack built in already, so there's no need for special mods or trying to mix sounds in your PC.

However, the only microphone that Canon sells to go with the camera is an expensive Bluetooth mono microphone kit, the WM-V1 Wireless Microphone.  All other microphones I saw had to connect to a special input shoe, and that shoe doesn't work with my camera.  Nobody else seems to sell any other mike or adapter for this camera, and I couldn't find any info on the pinout of the connector to make one myself.  

Somebody has got to figure out how to make an adapter and attach a reasonably-priced microphone or two to this camera...

I managed to dope out the pinout of the connector that plugs into the camera.  Incidentally, any camera that can use the WM-V1 Wireless Microphone kit uses this pinout, and just about every camcorder Canon makes is compatible with it.  If you want to see if this works with your camera, go to the Canon website, look under accessories/microphones, find the WM-V1 Wireless Microphone, and click the compatibility link to bring up a list of cameras that use this hookup.

It's a 4-wire 3.5mm (1/8 in.) jack.  It's set up for use with a typical consumer mike, and it can be used with a dynamic mike or an electret (condenser) mike.  Electret mikes need external power to function, and can have either two or three connections.  For a two-connector electret, the mike power and signal are carried on the same line, and for a 3-connector electret, the power and signal are separate.  A cellphone external mike uses 2 connectors, while a PC mike uses 3 connectors.

The Canon jack supplies mike power on a separate line, so you can ignore the mike power lead and use a dynamic mike, or use a cheap PC  mike powered by the camera.  Great!

This simple adapter uses the camera's power to run a typical PC microphone.  It's simple, and can be wired into the microphone jacks if there's enough room inside, and you know what you're doing.  When making this, remember that we are talking about extremely tiny, sensitive mike signals here, so you have to make sure everything is shielded - use shielded cable and metal jacks and sockets.

This adapter has two problems, though.  First, adding an additional mike (or two if you adapt it for stereo) may reduce camcorder battery life, and with a stock Vixia hf r300, we're talking a short battery even before adding additional power drains.  Second, PC mikes are designed to work with about 5Vdc going through a 2.2k resistor, and the Canon's voltage output is under 3Vdc and I don't know what kind of resistor it's through (maybe none).  Remember, this was designed to power their Bluetooth kit.  Because of all this, the mike's sound levels will be low, much lower than the camcorder's built-in mikes.  Not too bad of a problem with a good video/audio editing program, but it could be better.

To get around the battery life and low power level issues, it's best to ignore the camcorder's power supply and use an external battery and resistor to supply microphone power. To do this, I attached a 3-cell AA-size battery holder and resistor to the external mike I'm using, and just sent signal and shield/ground to the camera.  This is close enough to 5Vdc that it will work with no problems.  The batteries made a case necessary for this project, so I got a metal case which would fit the battery holder and obtained the necessary jacks and cable from either my hobby store or my personal supply.  Since we aren't connecting power through to the camera, a one- or two- conductor shielded cable is all that's necessary (no need for full-on three-conductor shielded cable, which isn't easy to find).

Once again, this thing's shielding has to be bulletproof.  For the case, scrape paint away from the screw holes and the input jack so everything has good continuity to the camera's cable shield.  

The setup above is what I'm using since I only need to record mono.  I've made a schematic for a stereo adapter as well, but I haven't tested it.  Should work, though.

OK, look - I'm trying to get by on the cheap here, and you're too rich and/or dedicated for me.  Mikes like that require 48V phantom power and balancing, and that's a bit much for my feeble skills.

That said, however, if you have professional mikes, chances are that you have pre-amps and possibly some mixing equipment and amplifiers and stuff.  If so, your equipment can probably produce a consumer line-level output for recording on DVD or PC or whatever.  If that's the case, you can use this circuit to convert the line-out signal from your setup to microphone input levels that are  compatible with the camcorder.

As before, I haven't tested this, but it should work, and if you have the ability to pot the signal up or down, you're all set.  The camcorder has a VU meter as part of the display (at least mine does), so adjusting your levels is a snap.

Shield everything, always.  Cheers folks!