PTA Posted September 4, 2013 Report Share Posted September 4, 2013 I thought I remember seeing this somewhere but I was unable to find it on the forums. Have any of you had trouble with the C300 when it is using something like an external V-lock battery or Anton Bauer to power everything while also powering your camera hop off of it's D-Tap or hirose? The one time I had to do this I remember getting a pretty nasty ground loop and had to power my QRX via its own battery. I thought someone may have posted a solution to this, or maybe not, but I was unable to find anything in a search. Has anyone ran into this and have a solution? Quote Link to comment Share on other sites More sharing options...
Marc Wielage Posted September 4, 2013 Report Share Posted September 4, 2013 The only time I encountered a ground loop in a camera audio situation was when the DP was monitoring the camera (a Canon 5D) with a laptop. The laptop was connected to an AC adapter, and that's where the problem was. Once they disconnected the laptop from AC, the problem went away. I suspect lifting a ground might have solved the problem as well, but we didn't have time to experiment. Quote Link to comment Share on other sites More sharing options...
Sndspd Posted September 4, 2013 Report Share Posted September 4, 2013 I had this issue a few months back with 3 C300 on an interview. The only way we could solve it was to rearrange which of 2 monitors that were AC'ed were going to which cameras. Also putting ground lifts on the 2 monitors. Unfortunately I heard the ground loop on the camera itself and my camera return to my Nomad so I had to deal with it; usually I'd only hear it on my return when it happens. I don't remember if any lighting was running off the same circuit as the monitors too. Gabe Quote Link to comment Share on other sites More sharing options...
Richard Thomas Posted September 4, 2013 Report Share Posted September 4, 2013 Quite a few guys over here seem to have had this problem, solutions seem to be either powering the rx separately or disconnecting the ground on the audio in. There's also a small audioroot transformer thing, which may do the job too: http://www.audioroot.fr/product/gle-8w/ Quote Link to comment Share on other sites More sharing options...
pindrop Posted September 4, 2013 Report Share Posted September 4, 2013 I've a special cable for this with the xlrs pin 1's both lifted. Quote Link to comment Share on other sites More sharing options...
PTA Posted September 4, 2013 Author Report Share Posted September 4, 2013 I've a special cable for this with the xlrs pin 1's both lifted. When you guys say lifted, do you mean that pin 1, the ground, on both XLRs is not connected? Quote Link to comment Share on other sites More sharing options...
pindrop Posted September 4, 2013 Report Share Posted September 4, 2013 When you guys say lifted, do you mean that pin 1, the ground, on both XLRs is not connected? Yes Quote Link to comment Share on other sites More sharing options...
Huxley Posted June 2, 2014 Report Share Posted June 2, 2014 We use a number of C300 cameras powered by Dionic90 battery mounted on the Anton Bauer QRC-CA940 battery bracket that provides -3- D-tap 12vdc outs and a pigtail from a Dc to Dc converter at 7.2vdc. We use the D-tap to power the SRA5P Lectro wireless receiver and pigtail to powwer the camera. And we have the hum or buzz problem in the audio. Separate batteries eliminates the problem but we don't need or want to operate a camera with 2 different type batteries causing us to also need 2 different chargers to carry around. Has to be a easier & better way. The Sescom inline IS-99 hum isolation transformers installed in the audio line fix the problem but they are too large to permanently mount on a C300. I've tried using a Switronics DC to DC converter and have the same problem. Appears to be a ground loup. Tried a ferrite bead in both dc lines still have the problem. Anyone figure out how to make an easy fix beside cutting off the pin 1 XLR audio in pin? Quote Link to comment Share on other sites More sharing options...
Rob Lewis Posted June 7, 2014 Report Share Posted June 7, 2014 If lifting pin 1 on one end of the XLR's is the solution, the easiest fix would be to make a set of cables for that camera with the grounds lifted. Cheap and easy. Quote Link to comment Share on other sites More sharing options...
Rich Reilly Posted April 8, 2015 Report Share Posted April 8, 2015 http://www.canon.com.au/en-AU/EOS-Professional/Product-Range/Cinema-EOS/EOS-C300-Mark-II Quote Link to comment Share on other sites More sharing options...
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