MixPre to GH2

L

Lee Saxon

Well-known member
For fun / on my own time stuff where I don't feel like dealing with dual system, but still want to use my external mic, I was thinking about going from the tape out on the MixPre directly into the GH2's audio jack.

Are there line-out vs mic-in (or vice versa) issues? What would I need to do this besides a 3.5mm-to-2.5mm cable?
 
If you're going to do that, you need to get a padded cable. Pumping a line-level signal into a mic-level input is a recipe for disaster, and potentially for damage to the camera's audio circuits.

Remember these challenges, though:

- You won't be able to monitor recording on the camera, only from the MixPre.
- Does the GH2 have defeatable AGC and manual audio controls? If not, your audio will be completely useless.
 
The GH2 has a 4 level AGC control. The best you can do is set it to level 1, and use a padded cable. I can't vouch for the results. People are using the Rove VideoMic Pro set to "0" db along with level "1" on the GH2 for decent results. I suppose if you don't push the levels too high on the MixPre you could get usable results.
 
Well, there you go. You're going to take a massive hit in quality by going in-camera this way.
 
But he can experiment by only getting a pad cable, which he should have anyway.

Lee I would be interested in your results if you could please make a little video demoing the setup. I own a MixPre, and may get a GH2. I'm still on the fence due to no 1080P30 and the AGC thing. Your video would be very helpful.
 
Yeah, my expectations for quality with this are not high. I've just found myself goofing around a lot (videos of friends and stuff) where I'm juuuust motivated enough to stick my 4053b on my rig and definitely not enough to go dual system.

Hopefully it'll be a noticeable improvement from the built-in mic, though. If only for positioning (pretty tired of hearing myself breathe :P )

I'll post a clip if I have any luck with it.

PS, on the GH2 - Are you talking about "real" 1080p30? Because it does have it in just an overcrank mode.
 
Yes I want to have 1080p30 with audio. I don't shoot anything in 24p. Even if I'm not using the audio I still need it for syncing purposes. I do a lot of stuff for TV and 24p don't work...
 
I think it's better just going into a recorder and mixing in post. It's not that hard! I'm doing it with four camera tracks and audio off the board right now by sight. No Plural Eyes needed, though I'm at the ragged edge of pushing the button, since I have PE installed. I only use the camera for the being able to find the starting point. It's the least of my problems (G). Doing quality sound on a HDSLR is just the wrong tool for the job. Trying to bother with a MixPre (I own one also) is a waste of time, when it comes to running signal into an inferior system. Remember the old silk purse from a sow's ear. Almost any recorder capable of 48kHz will do better than your camera's sound system. Been there, done it.

Hey Chadfish, saw your video on the Rode site. It convinced me that the Rode was better than my Azden, and on par with my Audiotechnica shotgun. I'll eventually need to get one for my 7D when my Azden cable frays.
 
I think for simple stuff you can get nice sound from a DSLR. I wouldn't do it for anything important, but for simplicity sake the option is there. The new FCP has a Plural Eyes-Like feature, so you'll be able to sync 2nd system audio without a 3rd party app. I can't wait!

I still want to hear what a MixPre sounds like going onto a GH2 set to "1". I test all the options, so I just gotta know...
 
Pads might work, depending.....

Pads might work, depending.....

My MixPre/GH2 works with a padded cable I bought five years ago from MiniDisco. I don't know the db drop, but it's 15kohms, and MiniDisco is out of business. It's the only pad from my collection of pads that works with the MixPre, and I attribute all my failures to the GH2's AGC circuit.

Aside from the mystery MiniDisco cable, I've tried Hosa XLR adapters (-20, -30, -40) and a few padded cables I made myself using RadioShack resistors (-25, -50). I also tried the mic-level output from a Mackie mixer. All failed! Although these tests were able to attenuate the MixPre to a usable level (excluding the Mackie test), the GH2's AGC circuit introduced various sonic anomalies such as massive hiss, major pumping, and locomotive-type sounds on any level the GH2 is set to. Miraculously, the mystery cable works (best at level 1) and that's the only cable I'll use with the MixPre. Making a trim pot would be my next experiment, but I think I'm done makin' things for now.

And I don't plan to buy the MixPre-D, but I'd be interested to know if any GH2 user has the MixPre-D and how its mic-level outputs interact with the GH2. We GH2 users don't have many choices like the Canon crew does, with Magic Lantern et al.
 
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