Audio Test with JuicedLink RA-333 Preamp and How To Properly Ground
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
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.
Rode NTG2 Condenser Shotgun Microphone
JuicedLink Audio Preamps for DSLR Video
Olivia,
With the new firmware update on the Canon 7D, does the need for a preamp with the AGC disable feature still necessary? I have been hearing from various sources online that you don’t need it anymore but I am skeptical on that.
@Casey You no longer need the AGC disable feature on a preamp with the newest 7D firmware upgrade.
Thanks for the retest.
The colors in this video look very pale and green. What were you lighting this with?
@Jason We were using ePhoto softbox lights with CFL bulbs.
Are you using a led panel for this… 1200 leds? It has a color cast for sure. Trying to decide about led panels and wondering if you can do a High CRI comaparison between to p end models vs the ephoto etc… my typing disappeared a minute ago off the box but i would love to see a high end panel vs the ephotos
If you watch the video review I did on the F&V lights (they have a very high CRI), I compare the color to an average inexpensive LED light, you can see a difference in color casts. I did NOT use ePhoto lights though. However, you could check in with the manufacturer and get CRI specs. This should give you a general idea about what the cast may look like. REVEIW HERE
Olivia, Robert, Anyone,
Did you use phantom power on the Rode NTG-2 or JuicedLink preamp? Is one way better than another?
@ProductUV both the JuicedLink and the Rode were running off of battery power. They work very well together and perform two different functions.
I would be grateful if you could tell me your settings of other devices: gain setup on Juicedlink and 5D Mark?
@Miika One click up form zero in the camera and then adjust on your meters in your juicedLink to be sure you’re not clipping. You want no preamp gain in-camera, only from the juicedLink which will replace the noisy gain with clean gain.