AGC disabler

R

Rehfield

Member
If this has been posted and discussed already, my apologies, I can't seem to find it.

I've found an ad popping up on CL for the AGC disabler described below. I'm hesitant to include the link, but there's a photo of it with the ad.

Anyone have experience with it?

_________________________


Sound Solution for Canon 5D MK II, 7D and T2i with AGC Problem
The “SILENCER” Micro AGC Disabler” is the low-cost sound solution for the AGC noise problem associated
with Canon 7D, 5D MK II and T2i EOS digital cameras. AGC stands for “Automatic Gain Control.”

It's a super-compact, light-weight, nickel-plated barrel adapter with a built-in resistor network that plugs in between
the camera and your external shotgun mic, or Lav mic; using a male stereo mini-plug to female XLR cable.

Canon EOS 5D MK II, 7D and the T2i have cheap built-in preamps which cause a loud, over-distorted signal and
other audio nightmares when using a pro shotgun mic such as Sennheiser, Audio Technica, AKG, Neumann and
Schoeps. Expensive audio mixers and other audio adapters such as the Beachtek and Juiced Link can solve this problem,
but they cost $400.00 and up.

The “SILENCER, “which retails for only $50.00, brings down the camera to mic audio level to where it should be,
thus producing a smooth, quiet, undistorted audio level and when the level is where it should be, the AGC
is not activated automatically. It also requires no batteries.
 
Sound Solution for Canon 5D MK II, 7D and T2i with AGC Problem
The “SILENCER” Micro AGC Disabler” is the low-cost sound solution for the AGC noise problem associated
with Canon 7D, 5D MK II and T2i EOS digital cameras. AGC stands for “Automatic Gain Control.”

It's a super-compact, light-weight, nickel-plated barrel adapter with a built-in resistor network that plugs in between
the camera and your external shotgun mic, or Lav mic; using a male stereo mini-plug to female XLR cable.

Canon EOS 5D MK II, 7D and the T2i have cheap built-in preamps which cause a loud, over-distorted signal and
other audio nightmares when using a pro shotgun mic such as Sennheiser, Audio Technica, AKG, Neumann and
Schoeps. Expensive audio mixers and other audio adapters such as the Beachtek and Juiced Link can solve this problem,
but they cost $400.00 and up.

:The “SILENCER, “which retails for only $50.00, brings down the camera to mic audio level to where it should be,
thus producing a smooth, quiet, undistorted audio level and when the level is where it should be, the AGC
is not activated automatically. It also requires no batteries.

$50.00 retail
Mention this CL post and receive $10.00 off

LA Distributor XXX, USA
Ask for Chris (818) xxx-xxxx

3kc3mc3od5T45Z35P0aa3e248a7cb60c41cfc.jpg




Location: LA
it's NOT ok to contact this poster with services or other commercial interests"
 
You get what you pay for. That's what this product seems like.

Unfortunately, there seems to be a major problem with this product; it only does half of the job. If you are going to lower the preamp on the camera, you need something else to raise the audio levels feeding into the camera.

With this adapter, you might get clean audio, but it will be recorded at about -60dB. Have fun trying to use that audio.

Oh, and the JuicedLink, etc. adapters aren't $400, like the ad says. I purchased the base model JuicedLink for under $200. The difference is the JuicedLink has it's own preamp to combat the lowering of the camera preamp.
 
Wait, I thought they stopped the adult ad section of Craig's list.....

:huh:
 
Anthony Arago said:
The difference is the JuicedLink has it's own preamp to combat the lowering of the camera preamp.
Click to expand...

This doesn't make sense to me - obviously the product that started this thread is just a bunch of resistors in a barrel connector to lower the audio by "X" db - you can buy a pad adapter that does the same thing.

It doesn't "lower" the camera's preamp in any way - there's no access to the level of the camera's preamp. Padding the signal and then boosting it seems pretty useless to me.

The claim for the product above (seems to be) that it keeps your signal below the threshold of the AGC (which is basically a compressor or brick-wall limiter). But without metering on the camera, you'd have to rely on your ears to tell when you've hit the limiter.

Most AGC circuits I've heard essentially raise the lowest levels of audio coming into the system (*notes below). Which gives that "breathing" effect, where room sound suddenly rises between dialogue or loud audio events.

Anyone tried using a pad to defeat AGC? I've never played with 550d/D90 audio at all. But if the camera's audio path has a lot of inherent noise, a lowered input level is going to cause problems in post.

The other solution is to feed a steady stream of white noise to one channel, causing the AGC to "clamp down" continuously across both channels; drawbacks are (a) you only get one audio channel and (b) cheaper cameras will get a lot of cross talk - white noise in your "good" channel.

*********

(* more accurate description: Actually what's happening in those cases isn't the room sound being amplified; the room sound is at the "right" level for the system, as they're usually amped up to get every last bit of audio a soccer mom might desire), and dialogue/etc is being lowered; if the release time - the amount of time the compressor holds that lowered level - is slow enough, there will be a few frames of quiet after dialogue, and you'll hear room noise ramp back up, giving a pumpy-breathing feel to the audio)
 
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