BMMCC assigning level control to 'line-in' vs microphone via s-bus?

[el chupacabra]

Line in audio levels can be controlled smoothly with S.Bus or PWM controllers same as zoom.
If you use external preamp with analogue gain control it is better to set camera levels to fixed default level somewhere around 90-100% and adjust analogue level on the preamp to avoid clipping.
Some external preamps have reference sound signal output so you can calibrate line in audio levels more precise.
I tested BMMCC with RMAA tests and found that it has very nice line-in quality noise level and dynamic range compare to average cameras and external audio recorders.

I can only get the OLR to change the 'microphone volume' (on board mic) in the BMMCC menu. I can't get it to change the 'line input' level. I can only change that thru the menu on the camera.

[Ryanite]

I can only get the OLR to change the 'microphone volume' (on board mic) in the BMMCC menu. I can't get it to change the 'line input' level. I can only change that thru the menu on the camera.

I believe if you have a mic attached into the 3.5 port then changing the microphone volume should change it, it should disable the on board mic and use the 3.5 jack instead. Set the cameras audio to Mic High. I think the problem your experiencing might be that the line input level isn't for use of an external mic but for using a pre-amp.

[Ryanite]

I can only get the OLR to change the 'microphone volume' (on board mic) in the BMMCC menu. I can't get it to change the 'line input' level. I can only change that thru the menu on the camera.

I believe if you have a mic attached into the 3.5 port then changing the microphone volume should change it, it should disable the on board mic and use the 3.5 jack instead. Set the cameras audio to Mic High. I think the problem your experiencing might be that the line input level isn't for use of an external mic but for using a pre-amp.

[david evans]

Not sure, I think when yiu set the camera to line level input, the camera sets the level at Unity +4Db, and you can not change it via the camera menu or SBus, that is how the Ursa Mini Pro works,

Denny, not sure I understood you correctly, but I can change gain in my Ursa Mini 4.6k, even when I'm using it in Line Level configuration. What I've been informed by the BMD support is that gain at 50% means that it's bypassing the camera's preamps. But I can definitly change the gain level by turning the volume knobs in the camera. I'm trying to find the best way to record sound into the camera, using a good preamp before the signal gets to the camera.

[el chupacabra]

for clarity:

you can change the internal pre-amp gain with sbus (or PWM)
you cannot change the mic input mode settings however (ie whether the camera treats the external mic input as mic or line level)

there seems to be some contradiction and/or confusion about whether internal pre-amp gain control is active or 'set to unity' when the mic mode is set to line level - I'd need to double check this on my own camera to be sure

I believe if you have a mic attached into the 3.5 port then changing the microphone volume should change it, it should disable the on board mic and use the 3.5 jack instead. Set the cameras audio to Mic High. I think the problem your experiencing might be that the line input level isn't for use of an external mic but for using a pre-amp.

On my camera it appears that even with an external mic plugged in, the camera records from its internal mic unless you switch the input from mic to line. With the mic plugged into the camera and the camera set to line input, I can not control the volume using the remote, nor does adjusting the level thru the camera menus effect the volume when the microphone is plugged into the line input.

Basically I thought once I plugged the mic in, the camera would switch the internal preamps to the external mic versus the internal camera mics. This does not seem to be the case.

[shijan]

- Turn Auto Gain Control OFF
- Set Audio Input to Inputs
- Set Input Levels to Mic or Line depending of your external audio source specs.
- Adjust Ch1 Volume Input to fine control volume level

- "Microphone level" volume affects only internal camera microphone volume so you can ignore it if use external microphone/

IMG_5950.jpg

[el chupacabra]

- Turn Auto Gain Control OFF
- Set Audio Input to Inputs
- Set Input Levels to Mic or Line depending of your external audio source specs.
- Adjust Ch1 Volume Input to fine control volume level

- "Microphone level" volume affects only internal camera microphone volume so you can ignore it if use external microphone/

IMG_5950.jpg

I follow this however, adjusting the line in put level makes no difference in gain whether it's set to 0 or 100 for me.

[shijan]

It is really strange. I was thinking maybe it is a another firmware bug, so i plug small external MixPre peramp with test signal line-out to camera line-in and found that in-camera volume control works as it should.
I never use on-camera mics but maybe some mics may communicate with camera in unknown way and disable input volume control adjustment?