Topic: Problems with Church-Audio CA14 plugged directly into Canon 5D MKII

[coolrat33]

Hi,
My friend is having trouble with his Church-Audio CA14 cards plugged directly into Canon 5D MKII.
He's experiencing a lot of noise.

However, I have a pair of Church-Audio CA11 omnis plugged into my Nikon D800 and have not really noticed any problems at all.

Of course it would be better to use my CA9200 pre-amp (or the cool pre-amp that Naiant built for me a few years ago with 72db gain), but I have not yet figured out a way to attach all that gear to my camera.
I've been using a box-frame cage (http://www.photographyandcinema.com/products/gearbox-gb-2-video-accessory-cage-w-15mm-rod-adapter), but I've been to lazy to mount and wire the whole thing.

My questions then:
1. What's happening with Church-Audio CA14 cards plugged directly into Canon 5D MKII?  Is a battery-box or pre-amp necessary?

2. Why am I not experiencing this problem on my D800?

3. Is it necessary to use a battery-box or pre-amp regardless of which camera I want to use? I'm not recording loud concerts- mainly conversations and daily life events.

Thanks for all and any advice!

[stevetoney]

A battery box is probably needed.  Those mics need power to drive them...the louder the recording the more voltage is needed.  The camera's mic jack is probably not designed to power more than the simplest of mics requiring low voltage.  It would be similar to the PIP jack on handheld decks...some of them provide enough voltage to allow the mics to work in many, if not most situations, but many of the handhelds don't work with the mics that we use.  I'm not sure, but the CA-11 may need less power than the CA-14, or it could be that the Nikon camera provides a little more voltage at the jack than the Canon.  Regardless, a battery box is the likely solution.

Note that alot of the mics that attach to a video camera are self-powered...they require a battery to be installed in them to function.

[Church-Audio]

A battery box is probably needed.  Those mics need power to drive them...the louder the recording the more voltage is needed.  The camera's mic jack is probably not designed to power more than the simplest of mics requiring low voltage.  It would be similar to the PIP jack on handheld decks...some of them provide enough voltage to allow the mics to work in many, if not most situations, but many of the handhelds don't work with the mics that we use.  I'm not sure, but the CA-11 may need less power than the CA-14, or it could be that the Nikon camera provides a little more voltage at the jack than the Canon.  Regardless, a battery box is the likely solution.

Note that alot of the mics that attach to a video camera are self-powered...they require a battery to be installed in them to function.

I would actually say that you would be better off with a 9200 preamp and use the output attenuator to drive the camera. You will have to play with levels. But it sounds like a classic case of AGC preamp getting cranked to get levels. Instead sending it a hotter signal that is attenuated so it does not overload the camera would be the best solution. I doubt the noise issue is a result of low voltage. But it would not be a good setup directly in anyway because the plug in power voltage would simply not be enough to guarantee no overloading.

[absnj]

The simple answer is to try your CA-11's in your friend's camera and visa-versa.  Since you already have the pre-amp, why not try it as well.

From my own experience, I have been able to run the CA-11's without a pre-amp, but not the CA-14's.

[Church-Audio]

The simple answer is to try your CA-11's in your friend's camera and visa-versa.  Since you already have the pre-amp, why not try it as well.

From my own experience, I have been able to run the CA-11's without a pre-amp, but not the CA-14's.

They both run the same actually. As far as requirements for power is concerned.

[coolrat33]

Thanks everyone.

I will try the various solutions including

1. using the mics with the CA-9200 Preamp.
2. using my CA-11 mics with the Canon MKII and check the sound quality. The CA-11 mics work on my Nikon D800 with no problems.
3. using the CA-14 mics on my Nikon D800.

I'll report back with the result. Is anyone else using CA-11 or CA-14 mics or similar mics on their DSLR cameras?

I mounted my CA-11s in a foam block that mounts on top of my hot-shoe. It gives about 6 inches (15 cm or so) of separation between the mics, which is probably better than nothing.
I have yet to carefully check the sound quality, but it seems good so far.

One other question:

I have a RODE NTG-2 with XLR output. (internal battery power or phantom). I run it with an internal battery all the time.  If I want to use it with my Nikon D800, can I just use a Rode XLR to Miniplug adapter (http://www.adorama.com/AURDVXLR.html?gclid=CJrZ8NP42bICFaaDQgodZRAAzw) and connect the NTG-2 directly to my Nikon D800?

[beatkilla]

not too many dslr users here bit check on www.dvinfo.net

[hoccusfoccus]

I do a bit cameras..

Sounds like AGC like Chris pointed out..

Canon offers (they finally listened to users) firmware updates that add manual audio control that stops the AGC cranking up the gain. Though this is dependant on which Canon you have as some of them haven't got firmware updates for this.

Some juice box (the competitor of beachtek) think had something that sends fake signal on other track to settle the AGC for given level.. but it's a hack and takes a channel..

Magic lantern might be a solution too.. it allows manual audio control + listening the recording while recording & can be loaded off SD card without overwriting the camera firmware...

5DmkIII has the manual audio control directly, 5DmkII may need the firmware update to do manual control .. less gain in camera the better and you may even need attenuator if too hot

When ever I shoot a film with DSLRs I don't bother touching their audio inputs and sync later (with good guide track/slates) instead with pluraleyes or use lockit timecode buddy.. these cameras are famous for breaking their main boards after HDMI connector getting yanked.. not for stressfull environments.. one guy killed the HDMI out by plugging into audio out when connectors were not labeled very good.. so watch out

And Canon still haven't come up for a solution to listen audio while recording.. magic lantern does support this but it's your risk and may not be compatible with your camera..

And by all means.. taken all these factors together & as the audio CODEC A/D converter in Canon is not that great.. use external recorder..