[Rick James]

Thanks Al. I’ve heard that about Canon service. We’ll be sending them in next week.

Cheers

[Rick James]

Thanks Ty. That seems to be the consensus even with the local Canon Certified tech who does “minor” repairs. If I find anything interesting I’ll post it here for anyone who stumbles upon this.

Cheers

[Rick James]

Hello Ty,

Thank you for taking the time to read my post and for your response. Btw this was my “first time poster, long time reader” post and I’ve read many helpful threads that included your posts over the years so I appreciate any input you and the community can offer.

Regarding your questions:

(RJ)…There is NO DISTORTION when the Shure SM87A mic is connected to Channel 1 with any of the XLR cables, (+48V was turned on in the camera). The +48V buzz and the white noise is still present.
(Ty)Are you monitoring each channel separately? Is the buzz and noise on both channels or in the unterminated channel 2?

Each channel was monitored separately and individually. The Buzz is heard on both channels. The white noise/static is heard in channel 1. It sounds like the normal camera noise and mic noise is being amplified in channel 1, while in channel 2 it is normal.

(Ty)When you find a mic/cable that works, keep the cable plugged into the camera and attach different mics to it to see how each one does. Also plug a mic and cable into inout 2 to properly terminate it.

I did this in the initial test but I tried it again to verify the results and they remain unchanged. However, I did find something that I did not notice before. Initially I found that the +48V buzz is not present in either channel when the Sony ECM-XM1 is connected to the camera with an XLR extension cable (it is present when plugged directly into the camera). The buzz is there with or without an extension in either channel with the Sony ECM-NV1. When I have both mic’s plugged in with an XLR extension cable, I hear the +48V buzz in whichever channel the NV1 is going to. If I send +48V to the NV1 with no phantom power going to the other mic, the level of the buzz is softer. Then when I send phantom power to the other channel, the buzz gets louder in whichever channel the NV1 is plugged into but there is still no buzz in the XM1. So, XM1 to Ch1 or 2 = BUZZ. XM1 + extension to Ch or 2 = NO BUZZ. NV1 +/- extension to Ch1 or 2 = BUZZ. NV1 +/- extension to Ch 1 or 2 AND +48V on Ch 1 & 2 = LOUDER BUZZ in NV1 but NO BUZZ in XM1.

The C100’s did not come with an external mic so we used a couple the Sony mic’s mentioned above. They were originally on a PD-170 and an HVR-Z7 or something similar. I’m not sure if this is useful information, but here are the only XLR input specs I could find for each of these cameras:
C100: XLR jack (pin1: shield, pin2: hot, pin3: cold), 2 sets. Sensitivity MIC setting: -60 dBu (manual volume center, full scale -18 dB) / 600
Ω LINE setting: 4 dBu (manual volume center, full scale -18 dB) / 10 k Microphone attenuator: 20 dB
HRV-Z7 (w/XM1 mic): XLR 3-pin, female, -48 dBu: 3kΩ (kilohms) +4 dBu: 10kΩ (kilohms) (0 dBu=0.775 Vrms)
PD-170 (w/NV1 mic): 3-pin female x 2, 327 mV, -60 dBu, 3 k Ω , +4 dBu, 10 k Ω (0 dBu = 0.775 Vrms)

(Ty)There may be some menu items in the C100 that need to be changed. I don’t know the camera that well, but I think I recall its menu structure is not that obvious.

I’ve tried many combinations of settings but none that I’ve found takes any of the issues away. Here are the usual settings:

I’ve searched pages and pages of google using countless keyword combinations trying to find anything resembling similarity to the issues I described and I did read about a lot of folks who have had noise issues when using Sony wireless lav’s like the UWP system with their C100’s (both Mk I and Mk II). The buzz/static signal they describe sounds much like the +48V buzz we have, but our buzz isn’t limited to only Sony wireless, it is present on any phantom powered mic and it is present when phantom power is turned on with no mic connected (I turned +48V on without termination only as an experiment, this is not a common practice). The solution they found was replacing the transmitter’s sony cable with a Sennheiser cable. This solution didn’t work for me on our Sony lav’s.

One more thing worth mentioning is that a 2013 firmware update for the C100 included modifying the XLR terminal polarity. I wasn’t with the company when the cameras were purchased or when the audio issues started and my coworkers have different views of when the audio issues started or if/when/which firmware updates were installed. From Canon firmware update 1.0.1.1.00:

The polarity balance of the XLR terminal has been modified to improve compatibility with external audio devices. The pin configuration has been modified to be consistent with the Instruction Manual. Before the Firmware update the pin configuration for the XLR jack was (pin1: shield, pin2: cold, pin3: hot). After the Firmware update the pin configuration for the XLR jack will be (pin1: shield, pin2: hot, pin3: cold). The XLR pin configuration meets the international AES standard recommendation. The firmware update will avoid the scenario where the unit if used in combination with a device of differing polarity of the XLR terminals, would result in weakened sound levels due to a reversal of the phase relationship.

This statement as well as the folks with the Sony lav noise issues, plus a couple of articles including this one: Phantom power could damage some microphone preamps as well (notably the second to last paragraph) is what made me wonder if this is a progressive issue that happened over time – not necessarily from one single issue. Whatever happened, it happened to both cameras around the same time. I don’t know much about the history of the cameras or if they ever had a line feed at the same event, etc.

I figure we’ll either send these in to Canon or replace the handle units but it would be nice to identify the problem and figure out what could have caused it so we don’t damage replacements.