In the video above, Robert from JuicedLink and I address how to properly ground your JuicedLink Preamp, in this case we are using the JuicedLink RA-333 Preamp. In an earlier video on the RA-333 coupled with the RODE NTG-2, we experienced some unwanted ground noise. Robert explains where the ground noise may have originated from and how to correct it with a proper setup of the RA-333.
How To Avoid Grounding Loops that create a Buzz in your Audio:
Ground Loops can result in a hum/buzz in your audio, and are created when multiple ground paths between pieces of equipment exist. You will always have one ground connection between the preamp and your camera, and that is via the shield in the stereo minijack cable that goes from the MIC OUT of the preamp into the MIC IN of the camera. However, depending on how/where you mount the preamp, a second ground connection can be created between the preamp enclosure and camera enclosure.
* The preamp enclosure is black anodized, which is non conductive. So, any elements in contact with the black anodized portion of the enclosure are not in contact with the enclosure ground
* Any silver parts of the enclosure, such as the female 1/4-20 tripod mounting hole, are electrically connected to the enclosure. So, any components in contact with these elements are also in contact with the enclosure ground.
* The camera mounting screw that goes through the preamp is suspended by nylon shoulder washers, so it is not in contact with the enclosure ground
Since we have our RA-333 connected to the top of the Canon 5D Mark III, we turn the ground switch to “NORM” this is a very important step to take while preping your setup so you do not run into ground noise.
We have the Rode NTG2 Condenser Shotgun Microphone boomed above and in the frame to show how we are orienting the microphone to best capture the signal, or our voices.
In the video, I also conducted an audio test that demonstrates the quality of audio with and without a preamp. I’m using the JuicedLink RA-333 Preamp (found here). The JuicedLink preamplifiers allow you to manually throttle back those noisy amps in the camera (which causes that loud hiss or floor noise) and boosts the signal with clean gain to achieve optimal signal to noise performance.
In an earlier OTech blog post about Preamplifiers, Robert from JuicedLink explains preamps, why you need them and how they perform for you and your workflow.audio, audio test, DSLR microphone, JuicedLink, microphone, NTG-2, polar pattern, preamp, quality microphone, RA333, Rode, RODE NTG-2, shotgun microphone, super cardioid, supercardioid, test