MA300 XLR microphone adapter

[Craig Hollenback]

If you are editing with FCP...you might see bioth VU "meters" going...this does not mean that the source is on both channels...just a thought...Best, Craig Hollenback

[John Aoki]

I am wondering if anyone with an MA-300 has used the BNC Video Output to a regular TV? I have tried it with several TV's using a BNC Composite cable and a Converter to TV Antenna Input - no luck! Has anyone been succesful with it?

[Tony Singh]

You won't be able to input to a TV's Cable/Antenna input.
You will have to go to one of the TV's Video Inputs. If you are using the Cable/Antenna input, you will first have to send the signal through a RF Modulator.

[Graham Bernard]

You will also need the little link cable supplied with your kit. This takes the Video "up" to the MA300. Without this it will not get to the MA300 - Canon didn't Wake and Smell the design Coffee in this case IMHO!!!

Grazie

[John Fitch]

Hi everyone.

Just wanted to post a quick question about the MA-300 XLR input adaptor for the GL2. From what I can tell, it doesn't look like the accessory piece itself has a mic/line selector switch for each XLR input, so does anyone know if there's a menu setting somewhere in the GL2 that allows the user to specify whether a mic or line level input is being sent to each of the two channels? I realize that the audio level for channels 1 and 2 can be adjusted manually using the audio level dials, but nonetheless I would think that in order to provide proper attenuation and prevent low audio or distortion, there should be a setting somewhere to specify whether the XLR inputs are being used as line or mic level audio inputs.

[Graham Bernard]

Excellent question!

[Craig Hollenback]

The beach teck adapter will let you spec line or mic. Also, it has a 1/8 jack pass through for wireless, etc.

[John Fitch]

While looking through a GL2 accessory overview (http://www.dvinfo.net/canongl2/articles/topfive.php#ma300), I found the following statement about the MA-300 XLR adaptor:

"If you need balanced audio connections for long cable runs, then you might want to consider a different third-party XLR adapter solution, as the MA-300 is intended for unbalanced nearby sources. "

Unbalanced sources? As long as I've been working with audio and video equipment, XLR connections have been considered balanced. Even Canon's instruction sheet for the MA-300 (which can be found in the "accessory manual" section GL2 website) indicates that the MA-300 is wired for balanced connections...pin 1 shielded, pin 2 hot, pin 3 cold. Am I missing something here?

[Chris Hurd]

Howdy from Texas,

I wrote that; sorry if it wasn't clear.

Basically, not all XLR cables and connectors are balanced -- some are, some aren't. The XLR connectors on the MA300 are unbalanced. Why? Because they don't need to be balanced, due to its intended use, which helps keep the cost down. The MA300 is meant for very short cable runs... either an onboard mic via the mic clamp on the MA300, or an onboard wireless mic receiver mounted on the accessory shoe on top of the MA300. These are extremely short cables, about twelve inches at most, with little chance of electrical interefence... therefore they're unbalanced (because they're not prone to hum by virtue of their on-camera location).

However, long cable runs across a studio floor, especially near sources of interference such as power cords, outlets, etc. will require balanced audio cables, and in order to preserve the protection that balanced XLR cables provide, they must terminate at a balanced XLR-to-RCA adapter, which the MA300 is not. For this job, you'll need a Beachtek (or Studio One or similar) balanced XLR adapter, which typically mounts below the camera, between the camera and tripod.

It's all a matter of choosing the right tool for the right job. For more info, see Jay Rose's excellent tutorial, "Balancing Act" which has scads more info about this topic. Hope this helps,

[Don Palomaki]

Check the MA-300 manual at:
http://www.canondv.com/downloads/accessory_manuals/ma-300.pdf
It indicates that the input is balanced. The output would be unbalanced, but that is not a big deal since it is mounted on the camcorder with essentially no lead length.

However, because the MA300 uses electronics rather than transformers, it does not provide the same isolation from the source as the SignVideo, Studio 1 or Beachtek would. For most users this is not an issue.

[Chris Hurd]

Thanks a lot, Don -- much appreciated!

[John Fitch]

Thanks for your input, guys. So with the MA-300 technical specs in mind, does this mean that the adapter does, in fact, provide true balanced inputs, or is the issue still kind of up in the air in your opinion? I guess if all three pins for each channel have an accessory shoe contact and go into the camera then the connection is balanced, however if the cold and shielded are combined somewhere along the line then the connection isn't truly balanced. With that in mind, is there really any way to tell whether or not the MA-300 provides a true balanced input connection?

[Don Palomaki]

The GL2 does NOT have balancd inputs, thus the MA-300 has to have a unbalanced output.

However, the input to the MA-300 is balanced, it provides the balancd to unbalanced conversion. If it is the same circuits as the MA-100, it does this using operational amplifiers. There are standard circuit arrangements for doing this.

The benefit of a balanced connection is noise reduction due to the common mode rejection of the amplifiers. (If the same signal is present at the + and - input, it is cancelled).

Because the MA300 is close-coupled to the camcorder (closer than the Beachtek, etc. would be), there is minimal chance for noise pickup in the couple inches of unbalanced connection between the MA-300 and the GL2's peamp.

[John Fitch]

Sorry if I'm beating a dead horse, but I'd like to see if I'm understanding Don's post. The way I now understand it, the MA-300 XLR inputs are, in fact, balanced, and so if I, for example, I were to connect the stereo XLR outputs of a mixer to the MA-300, I would have balanced outputs from the mixer going to the balanced inputs of the MA-300. That said, this connection would benefit from the advantages of using balanced connections...low interference for longer cable runs, etc. However, within the MA-300, circuitry provides a balanced to unbalanced connection for the audio signal actually going into the camera, so the signal going into the GL2 is actually unbalanced, however this makes little difference since the connection between the MA-300 and the GL2's audio circuitry is relatively short. Is this reasoning correct?

That said, aside from the fact that the Beachtek and other after-market XLR adaptors have features like level adjustments and so on, is it safe to conclude that the MA-300 is similar to these in terms of performing the balanced to unbalanced conversion?

[Don Palomaki]

Your summary is correct.

For most purposes the MA-300 and Beachteck, etc, will have similar perforamnce when use within their design operating envelope. However, the MA-300 (if like the MA-100/200) should be used with mic-level signals only (and it may offer some gain, which the Beachtek, etc. will not. ) It is not designed to use line level signals, and will go into clipping if you connect a typcial line level input to it. The -35 dB mic-level putput of most mixers is OK, the +4 dB level is NOT.