Now you don't have to solder like I did.

Dennis O’Clair from was nice enough to send me a cable to review to defeat or disable the AGC on the Canon DSLR like the 7D and T2i/550D.

It appears to be well made and works just fine as you can see in the video.

I think it is a little pricey at $26.95, but it is a very special cable that they mostly like will not make a ton of them. I made mine for a lot cheaper, but if you do not know how to solder this can be a big help.

To see what this cable does watch my popular video on my AGC hack.

You can purchase it here if you like. (I do not make any money off this cable).

Download the 19kHz tone (one hour long). To download from a PC, right click and “save target as” (unless you are really young you will not be able to hear this).


  • Hm, interesting idea. Is there anyway to adjust the sound levels with this configuration? (like turning down the volume on mp3 player?)

    For example, if someone was too loud or too soft and the camera’s automatic gain is disabled, how would you fix that?

  • @Yogo I have never had a problem with distortion hitting the camera audio inputs too hard. The AGC hack actually lowers the volume a bit but it works great.

  • I would buy this if they shipped to Ireland, it looks like a nice and simple solution although i’d be interested in hearing what happens with a single video clip with loud and soft noises

  • Hey Dave

    Once again this was great information. I actually contacted them and they price beat the other manufacturer of the cable. I also suggested to them they make a low profile version of the cable if they didn’t already have it…(L-Shaped)….

    Thanks again Dave for sharing! Can’t wait to post some new things as I go!


  • Hey Dave and everyone,

    I just ordered mine from Markertek Video Supply for a really nice guy named Robert Porcelli – Sales Associate who gave me a great customer service experience! He advised me they make the cables when ordered and also there may be a chance they can make the cable with a L to keep it low profile like the Rode connector is.

    Happy DSLR’ing – 🙂


  • A built-in tone generator. Now that’s a great idea. It adds cost though, but more convenient.

    Dave, I take it the audio on all your videos is recorded directly to the t2i? Using the Rode VideoMic? Have you used any other audio gear on your videos, e.g., lavaliers, external recorders?

    I also want to say I am very impressed with the quality of your videos in everyway. I saw that you’re using some very inexpensive worklights and softening that through some ripstop for lighting yourself — and I take it the sample with the flowers and lady. And that you’re using a couple more to light your green screen (or should I say white screen). This, to me, is simply amazing that you can get such high production value with inexpensive gear. I have started doing some videos for work, as an amateur, and it’s really challenging. I’m using an HV30 with Sennheiser G2 wireless system. But I’m on the verge of buying a t2i and your videos are quite convincing that this camera really delivers — when you know what you’re doing, of course.

    Thanks for such helpful videos and inspiration.


  • Dave… Check out this package from the 18th , it comes with pdf instructions , faq , it was quite easy.. You dont really modify the camera aside from a boot flag. I was good to go in 10 minutes. You may want to wait for others experiences.

    So far ive got audio levels on the screen, live histogram, crop marks, toggle AGC

  • I will try make a video showing the menus. Something interesting to note and a feature I was worried about. You dont even have to uninstall anything. If you insert a card that is not bootable your camera acts as OEM . So magic lantern only works with the card that is bootable and contains the proper files. So its quite easy to go back and forth! And it works with 1.09 firmware which was another welcome feature.

    Here is a video of the AGC test. (not mine)

    Here is another video showing some features.

  • Hey Dave the new Magic Lantern AGC hack for the T2i 1.0.9 update just came out, what do u think about it an would you ever put it on your T2j or would you recommend just using the mp3 way? thanks.

  • @Houston so who here is gong to do it first and share their experiences on video so we can all watch the process. Everyone thinks I am going to be the one – ha not going to happen!

  • Just got a Rode NTG-2 for my 7D this Christmas. Tried the 7D cable from Marketek with my MP3 and the downloaded tone. NOT working. Volume is very greatly reduced (almost inaudible) and the tone is very noticeable. Without the wire, the Rode works perfectly. I unfastened the connectors just to make sure nothing was shorting but it still didn’t work correctly.

    Guess I’ll just drop the cash on a Zoom and stop fooling around with work-arounds.

  • it would have been too much to have a link to an actually mp3? why would you post a link that just played instead of a link to an actual mp3 that I could save to my hard drive or device. you have wasted my time and i am very frustrated. everyone is not a super geek. you could make it easier if you really wanted to help!!!!!!!!!!!!!!!!!!!

  • How do I download the 19khz file? Every time I click the link it just begins playing with no download option. Help thanks!

  • I’ve been using my AGC disabler cable for a while now and it’s been great. Except yesterday I went to record something and my camera only picked up the audio from the tone and not from my mic. At first I thought maybe something was wrong with my mic. When I plugged just the mic in without the cable it worked fine. So I’m wondering if there’s something wrong with the mic part of my AGC disable cable (that rhymed). If you could help me out then that’d be great. Thanks Dave

  • Ozgur: rigth click “save target as”

    Dave: i’m from Chile and i’been following you for a while, so i have to say thank first at all, you are great and your work and totorials are really really useful, so thank again.

    see ya!

  • Hey Dave,
    Thanks so much for your ongoing video’s, this one especially helped a lot considering I was just about to order a Zoom H4n which would require me to spend a heap of time in post syncing the audio and visual perfectly.
    The one question I have is that I’m shooting on a Canon 60D which has auto and manual audio controls. When using the cable would it matter what option I shot on? Currently when I shoot directly through a Rode Videomic the manual control just adjusts the volume of the hiss caused by the AGC so in your opinion could I now be able to utilise this manual option by controlling the sound (which hopefully won’t have hiss!).
    If this is the case I should be able to use my external microphone, not have the AGC and be able to adjust the sound manually without it effecting the quality…all with this one cable 🙂

  • hey I watched your video and got an idea using 4 1K resistor and very high frequency for example 30khz (if we dont have low pass filter problem), inject the signal to both of channels using the resistors and connect also your stereo source via the resistors. the junction is on the plug 2 resistor for each channel.