View Full Version : HD110U noise
Joshua Frye March 26th, 2007, 07:47 AM Greetings.
I recently bought a new JVC GY-HD110u from a reputable source. I have full warranty coverage etc, but I thought I would throw this out here first before taking other action.
Problem; As most here are aware, unlike the 100, the 110 can power both the viewfinder and foldout LCD display simultaneously. I often fliped my LCD panel around and locked it into the body to have it display VU meters when shooting. I have noticed that while the LCD screen is on, a high frequency noice, very noticeable to me, is present in the headphone output and the sound recorded to tape, over both channels. The instant I close the screen, and it shuts off, the noise goes away. This can't be normal. What do you all think this is, and what do you think my COA should be? As of right now, I have ceased shooting with the LCD open, but this is sometimes not an option. Thanks for all your assistance.
Greg Corke March 26th, 2007, 10:58 AM Hi Joshua,
Mine does exactly the same. I think it may be a loose connection of some kind. I think my warranty is out now and did not get a chance to get it sorted which I'm now kicking myself for. As for your COA if it's still under warranty get it sorted out. If you can, However, take into JVC yourself where you can explain first hand what the problem is. I did this as JVC uk HQ was just down the road from me. I took it back to them to get the mode changing issue fixed and consequently saved a lot of hassle by the sounds of other peoples experiences going through their retailer. Hope you get it sorted. Like to hear how you get on.
Regards Greg
Carl Martin March 26th, 2007, 11:21 AM Greetings.
I recently bought a new JVC GY-HD110u from a reputable source. I have full warranty coverage etc, but I thought I would throw this out here first before taking other action.
Problem; As most here are aware, unlike the 100, the 110 can power both the viewfinder and foldout LCD display simultaneously. I often fliped my LCD panel around and locked it into the body to have it display VU meters when shooting. I have noticed that while the LCD screen is on, a high frequency noice, very noticeable to me, is present in the headphone output and the sound recorded to tape, over both channels. The instant I close the screen, and it shuts off, the noise goes away. This can't be normal. What do you all think this is, and what do you think my COA should be? As of right now, I have ceased shooting with the LCD open, but this is sometimes not an option. Thanks for all your assistance.
Did you use the core filters that came with the camera? If not, make sure you place them on the cable as close as possible to the connection input, and use them on all cables, Viewfinder, XLR's, DTE's, and headphone cable. They reduce the radio noise that you maybe experiencing.
Joshua Frye March 26th, 2007, 11:26 AM Core filters are in place as specified. This problem only happens when the LCD screen is open. When it is closed, the audio is 100% clean.
I guess I'll be getting in touch with JVC then.....
Adam Grunseth March 26th, 2007, 11:28 AM I'm not sure if this is at all related to your noise problem, but I thought I would throw this out there in the hope that it is useful to you. I have owned several PDA's in the past, and have occassionaly had ones that seemed to emit a very high pitch noise when they were turned on. Often the noise was not audible to me, I could only hear it in a quiet setting- but if I was out somewhere the ambient sounds would drown it out.... however if I ever used my PDA near a video camera, the camera would almost always pick up the the noise. The culprit appeared to be the LCD screen, as someone explained to me these LCD screens oscillate extremely minute amounts at very high frequencies. My solution for the PDAs were to open them up and use sticky insulating tape on the back of the LCD, as well as around the edges to cushion it- the sound completely went away. This didn't work for all PDAs though, with other PDAs I simply made sure the screen was fastened into the housing extremely firmly- this seemed to work as will, but not quite as good or with the same success rate as insulating it.
Of course if your camera is under warranty, I highly suggest you do not attempt any repair yourself.
Joshua Frye March 26th, 2007, 05:13 PM Interesting theory there, but the noise is picked up even with no microphones attached. My idea now is that there is some type of current leakage, or something with the internal camera electronics not in order. This is a minor annoyance, and I think it'll be business as usual until I can find some time to stand the camera down and send it in. Thanks for all the replies so far.
Carl Martin March 26th, 2007, 05:17 PM Core filters are in place as specified. This problem only happens when the LCD screen is open. When it is closed, the audio is 100% clean.
I guess I'll be getting in touch with JVC then.....
Yeah, maybe so. I know that 2 way radios sometimes interfere with certain cameras. I remember with my Betacam, when I would hit the transmit button, it would create noise and also would affect the Zoom on the camera. Either way I hope you figure it out.
Jad Meouchy March 26th, 2007, 05:53 PM It's not the LCD itself, but the LCD backlights or backlight inverter. LCDs are commonly lit with fluorescent tubes called CCFTs and they can grow noisy over time, or when electrical connections are not properly shielded. My guess is that there is a friction joint that has insufficient shielding/grounding and is causing electrical noise. This happens on laptops very often with the headphone jacks. It is very difficult to trace and fix without proper tools.
Try turning down the brightness of the LCD and see if the tone changes. Many people cannot hear such frequencies, so consider yourself 'lucky' that you have such good hearing.
The first thing you must check is if this noise is making it into your recorded signal. Most likely, it is not.
Joshua Frye March 26th, 2007, 08:31 PM More info to help narrow this down:
-Adjusting LCD brightness has no effect.
-The noise is heard only on audio channel 2.
-The noise is present in recordings.
-Turning off phantom, using different mics/audio sources has no effect.
-Camera's limiter has no effect.
-The noise is present even in record pause mode (so not linked to tape transport etc).
-It is present in all locations and is constant pitch and volume, so RF interference is unlikely.
-I think the noise is entering the signal after the gain stage lending credence to the current leakage theory.
So basically, nothing except for the fact that the LCD is on seems to affect it. Again, appreciate everybody's input.
Martin Guitar March 28th, 2007, 08:09 PM Can you send an audio sample from your channel 2 so i can hear the noise and compare. i'll try to do the same.
Martin Guitar March 28th, 2007, 08:33 PM To capture the sample, I unhooked the microphone and pointed it at the noisy area. (around the tape slot area) First i thought it was a normal tape noise but then after reading this thread i'm thinking there might be a problem... I also have to point that i raised the level of the soundbyte quite a bit so you can hear it well. It is not that loud in real life.
http://www.voicewalk.net/test/hd110u_noise.wav
Hope it helps.
mg
Carl Hicks March 29th, 2007, 06:07 AM To capture the sample, I unhooked the microphone and pointed it at the noisy area. (around the tape slot area) First i thought it was a normal tape noise but then after reading this thread i'm thinking there might be a problem... I also have to point that i raised the level of the soundbyte quite a bit so you can hear it well. It is not that loud in real life.
http://www.voicewalk.net/test/hd110u_noise.wav
Hope it helps.
mg
Hi Martin,
You should take your camera in for service at JVC Pro. There's a service center in Cypress, CA, close by you.
Greg Corke April 1st, 2007, 03:15 AM Just to clarify. The noise does stop when you press the panel at a certain place that the LCD sits in to. I would say it's almost definitely a loose connection of some kind creating the problem and not an abstract frequency.
G
As Carl has suggested take it into JVC.
|
|