MixPre 3 II powered via camera's V-mount creates noise in camera

[David Didato]

Has anyone experienced this? I've tried powering the RED Komodo via a V-Mount battery (through Core SWX adapter), and plugging the MixPre 3 II into either USB or Dtap out to USB-C.

 

The audio recorded on the MixPre is perfect as usual, but the audio on the camera (sent over a line-to-mic cable) has a significant static/buzz along with the mic(s) signal.

 

I've been using these two together with zero problems for years, Komodo + MixPre, BUT the MixPre was always powered via its own power source before. 

 

Obviously changing the power source is creating the problem, but why? Is there not a way to power everything on the camera off the v-mount? Anyone experienced this with other combinations?

Thanks,

David

[Blackdawg]

I found using the USB for power is always noisey. You're better off getting a power adapter sled for a Hirose connector and then can do a Hirose to Dtap and you'll be good. 

Cable techiques makes one. Hawk makes one and so do Sounddevices. 

[Larry Vaughn]

How does it work if you use a separate V-mount battery via usb C into the usb C port on the mixpre 6? 

[Mungo]

Major problem in setups when voltage converters are in use and the audio is not balanced.

 

One connection has to be isolated, either the power connection or the audio connection. Best is both of course, but one will eventually work.

Either a voltage separator / converter that has galvanic insulation (e.g. Tracopower)

or a separation filter in the audio path. The latter may decrease sound quality and increase noise, so I would stick to the first solution.