ML Analog Gain Setting when Using and External PreAmp

[66dellwood]

I use a BeachTek preamp to get better audio quality from my Canon 5D2.   I set to Manual recording in the Canon menu (not AGC) and set the recording level just a notch or two above the lowest level (so the preamp does the work).

Am a little unclear what the Magic Lantern Analog Gain setting is doing.   And how to set it when using the BeachTek.

Is it bypassing the Canon recording level?

Should I be setting it to 10dB or 0 when using an external preamp?

[dfort]

Wasn't Analog Gain removed a while ago? I believe it was just another way of adjusting the record level.

According to the user guide for version 2.3: http://wiki.magiclantern.fm/userguide#analog_gain_db

Analog Gain (dB)

Gain applied to both inputs in the analog domain. If you use an external preamp, set this parameter as low as possible; otherwise, set it as high as possible without clipping (audio meters should be green).

L-DigitalGain and R-DigitalGain (dB)

Digital gain applied to left and right channel. Recommended setting: 0.

[66dellwood]

Dfort, thanks much.  I still see analog gain at the top of my audio tab.  I missed that note in the manual.  Makes sense when using a preamp.

Curious how the gain setting in the ML menu interacts with the recording level setting in the main Canon menu.  From use, ML setting seems to override the Canon setting.

[markanini]

ML Audio settings override Canon settings. You probably want to keep analog gain in the camera at minimum and raise external preamp gain until the signal stays just below 0dB.

[66dellwood]

Mark:  thanks much.  Just what I hoped.  But ML only let you go down to 10dB.   I assume the 0dB level will cut off the signal entirely.

[markanini]

That's incorrect. 0dB is the baseline level, the others are amplification factors.

[66dellwood]

so 0dB may be a useful setting when using a preamp?