I finally figured out how to bypass or disable the AGC on Canon's T2i 550D and 7D using the Rode VideoMic.

As you can see by the video below I finally figured out how to disable or bypass the AGC (Automatic Gain Control) on my Canon T2i 550D while using the Rode VideoMic. (This will work for the Canon 7D as well).

I ran across a good video by Mike B at IamTheMikeB.com, he explain how to disable the AGC  which I had to give a try.

But I couldn’t get his hack to work for my Rode Videomic and judging the comments on his video no one else could either.

I made 3 trips to Radio Shack but none of these adapters worked. Don’t buy the ones I got if you have a Rode VideoMic.

I didn’t want to get a JuicedLink or a Zoom H4N or anything else that would add time and steps to my DSLR video workflow, I like to keep it cheap and simple.

Part 1

Part 2

Part 3 – Where You Can Buy The Cable

Perhaps someday Canon will be nice and provide a firmware update for the AGC, but I didn’t want to wait any longer.

The problem is Canon designed a poor automatic gain control AGC which would have been better if they left it out of the design all together.

What happens is if you talk really loud into the microphone the AGC will bring your level down which eliminates the hiss, but only 1 second later after you stop talking it brings the level all the way up again (along with the hiss).

What we want to do is clamp the AGC down and keep it there to keep the hiss away so we can have nice clean audio.

To do this I used an old cheap mp3 player I had collecting dust to playback a 1 hour 19kHz sine wave tone by sending the tone into the right channel of my T2i, and the Rode mic in the other. I like using the mp3 player because I can control just the right amount of tone to the right channel so I get the full clamping effect but not too much to have the tone bleed over to the mic channel.

What Mike B figured out which was the AGC worked in tandem for both channels which meant you only need to clamp down one channel while you use the other for your mic.

Now what really screwed me up was the audio adapters from Radio Shack, I pinned them out with my multi-meter but I couldn’t understand why it was not working when other mics worked fine, so I then tried using my alligator clips to figure out how the Rode video mic was wired and that is when I found the answer.

The Rode Videomic connector was not wired like I thought, normally on most mikes you just need the tip and the ring, but with the Rode mic you need to carry the sleeve in your connections (something the Radio Shack adapter won’t do).

I created my own adapter with the tip and sleeve carried through and it worked perfectly!

So what I do when I bring the audio track in to Sony Vegas is to right click on the track and click on left track only and I am good to go since the Rode mic is mono anyway and only needs one channel.

In my next video I will show you how I wired it up. I should have that done soon.

Download the 19kHz tone (one hour long). (unless you are really young you will not be able to hear this).

Update 1:

One of my reader Salvic is making this cable for sale.


  • Wow small DSLR world. Mike is a friend of mine here in the Bay Area. I had seen his tutorial but hadn’t given it a try yet. I’ll have to try yours. Awesome, thanks Dave!

  • Very nice and clear instructions. Love the B-Roll soldering footage. I’ve seen this done before and it works great for in camera audio processing. I used the Magic Lantern firmware shortly after playing with my 5D. That AGC hissing noise was annoying me! Great job on this one.


  • Can’t wait for part 2! I have been trying to do this with the Mike B method but I can’t get it to work!

  • Great Video Dave, I am also excited about part two. Audio is the area I need the most improvement. I am trying to find a simple solution like you.

  • Doh! I wish you had discovered this a few months ago before I spent $300 on an H4n!! : – p

    Very clever hack. I like it.

  • Hello Dave,

    your video might just save my movie here.

    I would absolutely love to see part 2 and actually see what i need to do this thing work. Do you think you’ll be able to post that video before 12-th July?
    If not is there any way you can show schematically how you wired those things and what you used.

    Thank a lot.


  • Thanks Dave,

    i have already tried myself soldering somthing, but my problem is that even if I convey a signal from left (or right) mono the final signal (at the camera) arrives with left channel loud and the right channel low but still hearable. I think im doing somthing wrong 🙁


  • I am using a desktop microphone for tests..

    I have created a splitter from a stereo jack with the tip and sleep to mono 1 (mp3 player) and ring and sleeve to mono2 (microphone)…

    I’m dying to see your idea.

  • I did it 🙂

    I will let you explain to others though, cause it’s your blog.

    Good luck 🙂


  • Good idea. I’m back, thinking out loud again, and as always throwing ideas around…

    I wonder if the 19KHz tone may be too high. Nice to have it up there so it has less chance of feeding through to the other channel, but the AGC might be a little rolled off at high frequencies. Seems to work fine with this tone on this camera, but I wonder if it might not on others.

    On the RShack adapter, I am surprised you say the sleeve is not linked through. If it’s not they would not work with headphones as the sleeve is essential for the return signal for the two channels being fed. You must have a faulty one. Without the sleeve being passed through you’d have a Hafler effect.

    On the wiring of the Rode mic. When you unbalance this, you clipped off the black wire. Should you not have connected this towards the ground as is done in normal mic’s when unbalancing? Usually the cable is wired Tip to Tip, and Sleeve to “Sleeve and return.” Leaving the black “not pulled low” might be part of the hum you are introducing on long cables. As you say though, don’t use a long unbalanced cable, ever.

    Cool stuff as always. Keep up the good work.

  • I’ve purchased Rode Videomic exactly to be used with this camera and right on my first test I was impressed (negatively) by the extreme loud noise I had in my audio.
    I did a little research on several webpages and found this one with this great tutorial! And I made it! I could get my Rode Videomic to work with almost no noise in the audio track and it wasn’t necessary to do any soldering. Simple and efficient!

    However the amplitude of the sound I now get form the mic is much lower than before. Since I’m using this mic in studio I won’t have any problems getting the sound I want but I wonder why this happens…

    Anyways, thank you for your kindness on posting this workaround. It will certainly help many video producers that want their Rodeo Mics working harmoniously with their TSI/550D or even 7D.

  • Still waiting to see if anyone has discovered a splitter that will work with the rode videomic out of the package. If so, please let us know!

  • Hi Everyone,

    First of all, thank you Dave for this solution, It helped me save a lot of money.

    Before getting into the soldering option, I tried to do it with a couple of adapters to see if this could work.

    So here is my “cheap and dirty” temporary solution : Jack to RCA splitter.
    This requires additional adapters that will bring more static noise from the environment but it is definitely an easy solution that doesn’t require any soldering.

    The cable I used is a Griffin Tech that I already owned.

    Apparently they are not selling it anymore, but I would guess that you may find similar products easily. I tried before with Jack splitter but as Dave mentioned, they are not wired correctly.

    On the Rode end, you connect this : RCA male to 1,8inch Jack female

    On the mp3 player end : stereo RCA male to 1.8inch stereo Jack (haven’t found any mono Jack-RCA cable). .
    You connect only one end of the Y cable (the other end stays unplugged to benefit from static noise problems… I told you this was a cheap solution)

    Next step for me:
    Because I am not a pro at soldering but not afraid to try, I will try to take a Y cable (RCA to Jack) and replace both RCA ends with a male (Rode end) and a female Jack (Ipod end). This will simplify the soldering a lot (no hard three-wire coming from two cables soldering to do).

    Those were my two cents, let’s keep our finger crossed that Canon may put an option to remove the AGC…

    Best and thank you again for this solution,

    Simon from Paris/France

  • Sorry one more question…
    But what kind of lens? I like the d.o.f.
    And do you just have the mic straight in the camera? or a recorder?

  • Simon did ur method work?…. can I see a pic of the finished cable?… Thx Dave for this work around

  • thank you! Man that’s awesome but a lot of work. But i’m going to give it a try… it’s fun tinkering with stuff. i wish someone would just write software for this AGC thing though…

  • So, with @Simon’s method, can I just solder on mono male and female parts to the cut off stereo cable? Or do I need a stereo jack to convert down to mono?

    I am really close to understanding this but it is just slightly over my head.

    Can anyone make a sketch of the @Simon method, and does that work?

  • This a great solution and works well, I did all my testing with an SQN mixer and psuhed a 1Khz audible tone into one channel and a mic into the other. This is not advised as a solution as the audible tone leaks over to the other channel but it certainly proved the theory.

    Just for your reference, the AGC causes no problems when recording in a live gig with lots of noise and an external stereo mic. I am a hobbyist and I use the 550d/T2i to film live rock and variously use a Sony ECM-959 or ECM-969 external stereo mic thru a 2 x XLR to 3.5mm plug and my recordings do not contain any of the characteristic AGC hiss, although to be fair there is a lot of noise and there are not too many silent gaps! I just sold my 2 Canon XL2 pro video cams to make the DSLR switchover and was really nervous about my first shoot.

    I have experimented with different volume levels on my XLR adaptor and have finally settled on max volume to the Canon. The XLR adaptor is a passive device that has no battery and does not preamp the mic signal. The brand is Audio Balun and it would be about 15-20 years old.

    I do not recommend the Rode Stereo Vidmic, I also have once of these and even with the 10dB PAD the mic distorts very badly in live gigs, it is totally unusable. The Sony ECM-959 & 969 mics I use are about 15-20 years old and have a wide angle adjustment one them from 90 deg to 150 degrees. When I widen them up they never distort and I get pretty good live recordings from them.

    I have only filmed once last week using the 550d and the environment was truly awful. There were NO LIGHTS at all, the vocal PA was 2 puny speakers and so all the vocals were distorted at the gig. If you listen to the recording of the 550d you will notice that the guitars, drums, etc are not distorted but the vocals are shocking, worst PA I have ever encountered.

    When I got home to look at my footage it was almost all completely black due to no lights whatsoever, the band played in almost complete darkness, lol. I used photoshop to increase Luma and then used RGB curves to drive some colour into it and lastly I put on about a 4% blur to kill some of the inevitable grain.

    It’s a bit wobbly and I used my cheapo Canon F1.8 50mm set to auto mode in video but I was pleased to see the potential for video with this camera in shocking conditions. Because the venue was about 2-3 times the size of the average home lounge I was pressed up against the bar about 3M back from the band.

    Canon 550d/T2i F1.8 / 50mm Mounted on Manfrotto Monopod about 2.2M up, Sony ECM-959 Stereo mic in to 2 x XLR into Audio Balun XLR to 3.5mm adaptor, max output levels.


    This band wanted a “low rent” garage style shoot so virtually no editing or effects, they certainly got that, lol.



  • Hello,

    I am trying to put the tone onto my mp3 player and I am having trouble……do you have any suggestions.


  • Hi Dave watched your tutorials and I envy your technological DIY mentality. When you are using this adapter do you have to edit out the 19khz sound in one channel? I ask this because I noticed on the youtube video where he suggests using the Y-adapter he also says at the end that you will need to choose the correct channel in your editing program. BTW did you find anywhere to buy one of these adapters?


  • Did something happen to the downloadable audio file? It is not downloading right for me, and won’t play on it’s own webpage.

  • Thank you very much for all the help and advice.

    To sum all this as a new owner to aT2i, should I not get a Rode Videomic until MagicLantern have made a crack (for audio) or these type of cables are sold as a set? (I’m not very good in electricity…)

    I mean, is there a significant difference using the Rode mic (with the noise..) than the built-in mic? Is it still worth the money?

  • Hi!
    Is it just fore me the 19khz sounds like a helicopter!? and that helicopter sound destroys the normal sound in the left chanel!? it´s not working god at all… 🙁

    Tanks for a good website!

  • Hey try this so you don’t have to solder one yourself or if your local shop does not sell a stereo to mono adapter. http://www.chungdha.com/2010/11/how-to-wire-dslr-for-audio.html

    It is more wires but it works and if Canon Comes with an AGC atleast you can also use this setup for a double microphone with separate channels. Also show how to listen to the playback with a headphone so you are listening to only the recorded sound you want to hear and not the agc hack sound.

    Kind regards,

    Chung Dha

  • Any idea if this fix will work for the Canon EOS 60D?

    It has Manual audio available but when either of my External Mics are hooked up there is still an audible background hiss that is super annoying.

    My shotgun is an AT-897 and my Lapel mic is an AT-831-SP. They are both powered. Both have the same noise.

    I’m either going to have to get an external audio recorder or if your fix works that would be fantastic.


  • I bought the splitter thinking it would work with my azden smx-10 and it dosnt seem to work. it works with other handheld mics that i have but not with the my camera mount one. do you know why it might not work?

  • @Luke I bet it is because the mic is wired differently inside, like pin 2 hot which might be opposite of the Rode mic.

  • thanks, i will have to look for a new mic it seems. have you heard of any other mics that it has worked with besides the rode?

  • How can I download the 19kHz tone? if ik click on the lick it opens a new tab in my browser with just a quicktime player..

  • it worked, thanks!

    i really appreciate what you’re doing, i did/do learn a lot from your vids!

  • I’m hoping you have a wiring schematic for the cable, I’ve tried to watch the video and I see your sketch of how it should work, but I always have trouble following. If you could show me where I can find the schematic, I would greatly appreciate it!

    I have soldering skills, so I figured I can make one faster and cheaper than ordering one. Thanks!

  • Great tips and website! Question, curious why you’d go through all the soldering and figuring out if you could simply install magic lantern and disable AGC that way?

    I’m a big time novice at all this, and haven’t tried either.


  • In reference to ~3:00 of your part 2 video, I actually came across a simple Y-splitter that DOES share the sleeve. In fact, instead of a molded part, it’s a box part that you can crack open and clearly shows the P-bronze contacts being shared across both plugs. You could either bend back or snip the tip and ring, respectively, from either plug, effectively giving you the L/R separation splitter in a neat little box.

    Thanks for your video and tech tip… I plan to do this myself so I don’t have to install Magic Lantern on all my cards 🙂

  • Just tried the sescom agcy cable, your 19khz signal, a rode videomic pro, and my 7d without success. I’m using final cut X and when I split the audio into two mono channels I still get the recording from my mic on both. Help!

  • Hey dave

    I got the cable and the 19khz tone. Im still getting some noise in the backround, and if i turn up the MP3 player, i just get a beeping noise. Could you help me out on this one?


  • There is a hack around this problem, it’s called Magic lantern with this hack you can disable the agc completely and have a normal level controle with audio meters very good solution, just go there and find it out.


  • I use a simple sony stereo mic and put the hack at external stereo mic power on (low Z) audio meters ‘on’ monitoring usb ; on you can monitor through the output cable via a headset and usual I put the level adjust on 10 or 18 dB that depends of the loudness of the event, usually my own performance with several musically projects. see my site to check the vids.
    So if you want the Rode-videomic pro to work you need to figure out how to get a stereoout at the minijack tip is left, ring is right and sleeve is earth.
    I took a look at the specs on the site of Rode and the output is just stereo to minijack so it should work

  • Thank you, Oscar! Now I am trying to download the 19kHz Sine Wave, but it will not download! I don’t even get an option to download it. It just asks me if I want to buy Quicktime Pro???? Huh? Does anyone know how to help me? Thank you!

  • I was going to order a rode videomic; glad i didn’t. This is just out of my tech skill. I guess i’ll just have to continue to use the camera mic. Wish there was a plug and play solution for me?

  • Hi,

    You can go to magiclantern.fm and download magic lantern which runs off your SD card and in the settings you are able to turn off the AGC as well as do a load of other things.

    Also you can plug a clip mic directly into the mic socket of the T2i which works really well. Then listen to the audio through headphones on the monitor socket on the clip mic receiver or via a special cable from the AV port to headphones.

    Nice videos

  • Hello,

    I have the SESCOM disabling cable. Can I use a computer as the generator for the 19 hkz tone? I tried using my computer but I either got no AGC suppression, or just a blaring tone (that was clearly audible) over everything. There was no middle ground. I don’t know if it’s the 19 khz tone you supplied or the fact that I’m using a computer as the gen. Help please!

Signup for Dave’s Newsletter (not working)

  • 4hourcourse1.jpg