2.0.4 firmware and SoundDevices MixPre

[Thierry Humeau]

I see that the 2.0.4 firmware allows for manually adjusting audio levels on the D5. Sounds like SoundDevices's MixPre would be a perfect device to feed quality audio into the camera. Has anyone tried it yet with 2.0.4?

[Jon Fairhurst]

I haven't used the MixPre, but I've used the juicedLink CX231.

Regarding firmware, the sound is cleaner with Magic Lantern 0.1.8 alpha on Canon's 2.0.4 firmware than with the stock 2.0.4 firmware alone. The reason is that the stock firmware sets a high analog gain and does the rest of the gain control digitally. With ML, we can alter the analog gain and digital gain independently.

Regarding the MixPre, note that the Canon expects a mic level, rather than line level. You might need to pad the MixPre output. And, it's unbalanced, so you want the preamp right next to the camera.

Given all that, I think the JL is the better functional match - the gain is super clean, the levels are right, and it's made to be right next to the camera. If you want, you could run a field mixer with a long XLR run to the JL and camera. The JL has a line/mic switch for its inputs.

[Dan Chung]

Thierry,

I have the Mixpre and the Juicedlink CX231. You can see my early tests with the MixPre here Testing the new 5DmkII 2.0.3 firmware on a news assignment DSLR News Shooter

You do need to PAD the output either from XLR or tape out. Personally I like the VU meters as they are very accurate, the headphone output on the Mixpre is top class too. That said I am now eagerly awaiting the new Juicedlink DT454 Camcorder XLR Audio Adapter/Preamp: Buy Direct and Save

Dan

[Kirk Candlish]

Originally Posted by Jon Fairhurst

I haven't used the MixPre...

Regarding the MixPre, note that the Canon expects a mic level, rather than line level. You might need to pad the MixPre output. And, it's unbalanced, so you want the preamp right next to the camera.

Clearly you haven't used the MixPre and don't know what you're talking about.

From the SD MP manual:

Output Circuitry and Tape Output
Each line level XLR output of the MixPre uses an active-balanced output stage. The circuit provides robust line driving capability. To drive unbalanced inputs, pin-3 should not be connected. When unbal- ancing the connection the output level will be reduced by 6 dB.
The Tape Output is designed to feed consumer level devices, such as computer sound cards, DAT or MiniDisc recorders, and cassette recorders. A cable wired with 3.5 mm TRS to 3.5 mm TRS or, 3.5 mm TRS to Left/Right phono (RCA) connectors, is useful when directly connecting the MixPre to portable consumer audio electronics.

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I run 30' of unbalanced cable from the tape outs on my SD302 to the 5D and get very good audio, though it's only a reference track. Unless you're dealing with a tremendous amount of interference in your shooting environment unbalanced is not an issue.

From the SD MP fact sheet:

RF filtering on all inputs and outputs. Free from "Pin 1" grounding problems

[Jon Goodman]

This may be of interest.


Audio Performance of Canon 5D Mark II Camera|Sound Notes|Sound Devices, LLC

[Jon Fairhurst]

Originally Posted by Kirk Candlish

Clearly you haven't used the MixPre and don't know what you're talking about.

No, I haven't used the MixPre, but I believe that I know what I'm talking about.

The camera has an unbalanced input. You don't want to used a long, unbalanced run. If you do so, you risk picking up RF. Sometimes, you can get away with a 30' run. But if the wire is near an AC line or RF source, your audio can be ruined.

If you want to run any line level, balanced mixer far from the camera (not just the MixPre), then I would recommend using an XLR to unbalanced adapter with a transformer near the camera, and to place the pad as close to the camera input as possible on the unbalanced line. That adds the problem of mechanically mounting the XLR adapters so they don't add mechanical stress to the camera.

My point wasn't that the MixPre is bad, just that it's a bit more of a hassle to connect to the camera properly when used remotely. (Pad, adapters, mechanical mounting.) With the JL, you just screw it to the camera and plug it in.

[Bill Binder]

Originally Posted by Kirk Candlish

Clearly you haven't used the MixPre and don't know what you're talking about.

From the SD MP manual:

Output Circuitry and Tape Output
Each line level XLR output of the MixPre uses an active-balanced output stage. The circuit provides robust line driving capability. To drive unbalanced inputs, pin-3 should not be connected. When unbal- ancing the connection the output level will be reduced by 6 dB.
The Tape Output is designed to feed consumer level devices, such as computer sound cards, DAT or MiniDisc recorders, and cassette recorders. A cable wired with 3.5 mm TRS to 3.5 mm TRS or, 3.5 mm TRS to Left/Right phono (RCA) connectors, is useful when directly connecting the MixPre to portable consumer audio electronics.

------

I run 30' of unbalanced cable from the tape outs on my SD302 to the 5D and get very good audio, though it's only a reference track. Unless you're dealing with a tremendous amount of interference in your shooting environment unbalanced is not an issue.

From the SD MP fact sheet:

RF filtering on all inputs and outputs. Free from "Pin 1" grounding problems

Wow, that's a bit harsh, especially considering how wrong you are, LOL.

John wasn't saying the MixPre didn't have balanced outputs, he was saying that your run from the MixPre to the camera would be unbalanced and he is correct.

For starters, the Tape Output is NOT balanced by definition, and what you just posted actually backs that up. It's impossible for the tape out to be balanced. Furthermore, if you use any sort of adapter(s) to take the XLR outs of the MixPre into the single minijack of the 5D2 or 7D, that won't be balanced either because you will have DEFEATED the balanced run at that point.

So, actually... Pretty much any connection you make from the MixPre to the camera WILL IN FACT BE UNBALANCED because the camera itself doesn't have balanced inputs. The only exception to that fact would be if you stuck another piece of gear (transformer) between the MixPre and the camera, then you could get a balanced run to the additional device and unbalanced from the device to the camera. Whether unbalanced is a problem or not is a completely different matter.

[Chris Barcellos]

In response to this thread, I finally got out my old Beachtek XLR adapter ( I also have the Juiced Link CX231) and my Sign Video ENG44 and ran it with my 5D just to get a feel for what it can do. While I didn't immediately hit on the right combination of settings, since there are at least 5 different adjusting points (mic level into the ENG44, output level on the ENG 44, mic or line level out switch on the ENG44, the pad level adjustments on the XLR adapter, and of course the level adjustment in the camera), it appears to me in the brief playing around, that I will, with sometesting be able to arrive at a great set up.

For you sound freaks, I assume the best use of the unpowered XLR adapter in this case is to set it at highest levels on one channel (which should give me unaltered signal ?) and set the other one down a bit, to give me safety on the second channel. From there, I assume I want to keep the camera at no more than three or four clicks above 0, by sending a 1K tone from the mixer to the camera, adjusting the output level from mixer, to get camera hitting about the -12db mark. From there, you adjust the mic input level, as needed for your sound source. Any comments about that approach.

I have found that output switch has to be set a mic level out of the ENG44. Is that consistent with others ?

[Thierry Humeau]

Thanks guys, however, I did not want to start such a heated discussion... In regard to the responses above, I feel that indeed, the MixPre may be an excellent device to use with the 5D and the 2.0.4 firmware since there is no need to defeat the camera AGC anymore. The only drawback being that it won't mount underneath the D5 but on every other aspect such as built and sound quality, levels and sound monitoring, the MixPre should yield excellent results. We have used SoundDevices mixers for several years with conventional video gear and they are absolutely fantastic mixers. As for running an unbalanced line from the MixPre Tape Out, I don't think it will be a problem as I plan to keep that line pretty short, around 6' or so. Thanks again for the feedback.

[Daniel Jackson]

I believe that length of the cable to the camera from the mixpre is not a huge issue because the levels are already boosted by the preamp. If it were a weak mic signal going through a thin unbalanced unshielded line it would pick up noise and hum, but a line level is much more robust.

[Tony Davies-Patrick]

I would love to use my Canon 5D with mic connected directly to the body, but even with the new firmware upgrade for Manual audio levels control and various help from Juiced Link/Beachtek devices etc., I've yet to hear really nice clean captured sound from the 5D.

Dual-System Audio is the only viable option I've found that will give me nice clean sound with good bass etc and at a professional level. It can be a big bind, especially with some of the run-n-gun stuff I often need to do, but I can't at the moment see another way of obtaining top-grade audio. Sound is sometimes just as important, and often more important than picture quality, so it is vital to get it right.

[Thierry Humeau]

Originally Posted by Jon Goodman

This may be of interest.


Audio Performance of Canon 5D Mark II Camera|Sound Notes|Sound Devices, LLC

Excellent info. Good to hear it from the horse mouth... Thanks for the link.

[Jon Fairhurst]

Note that you can get about 9dB more S/N by running Magic Lantern 0.1.8 alpha.

I have a readout of the registers in the Canon audio chip. I'll see if the HPF is enabled. If so, ML will probably be able to get a fuller bandwidth signal. It would be nice for this to be switchable, with the default ON. (I say ON by default, because most people use it for recording dialog, and the HPF reduces wind and handling noise.)

[Bill Binder]

Originally Posted by Jon Goodman

This may be of interest.


Audio Performance of Canon 5D Mark II Camera|Sound Notes|Sound Devices, LLC

Wow, that was EASILY the most articulate, informed, useful, and dead-on (IMHO) assessment/review of the audio signal path in the Canon 5D2 that I've ever read anywhere on the Net to date.

Well done Sound Devices, well done! Not that I expect anything but the highest quality from them, I guess that even applies to their website, LOL.

Take that info plus John's info about the improved S/N ratio of ML (see above), and you pretty much have the whole story about 5D2 audio -- all the info needed to make an informed decision about which way to go for your specific application.

.

[Daniel Jackson]

Hi Dan,
Why use the xlr to minijack? Is it because the xlr wont fall out as easily as the minijack?

also

Is the pad necessary when the 5d's gain is all the way down?

Thanks