PD170 Line noise when no mic connected at DVinfo.net

Edwin Rutsch · May 17th, 2009, 02:31 PM

I was dealing with some audio problems with my pd170. I noticed that when there is no mic connected to either inputs and I turn up the levels to 100%, that I hear line noise.

you can see the wave form here.
pd170 audio problem wave form

when there is no Mic connected to input 1 or input 2,

Levels turned up above 60%
and the levels are turned up high, above 60 or 70%,
then there is a background noise in the ear phones and on the tape audio.
first part wave from below is level up high, about 100%,
someone told me there is always pre amp noise, but is this normal?

with level around 50%
I don't hear the line noise
but if I tape and import the clip, then up the gain 20 db or so, I see the line noise.
in both cases you can see background noise.
Below is is the wave form expanded way up.

on the line is a periodic brrrrrrrrrttt ------ brrrrrrrrrttt - sound

I saw there was old problem with line noise on pd170 when opening the flipout lcd, but this audio noise happens all the time.

Problem 2 - Sennheiser K6 and ME 64
the other problem I have is with a Sennheiser K6 and ME 64
there's a loud hum. when I replace the k6 modual with another one it goes away.

thanks for any help on this.

edwin

John Peterson · May 18th, 2009, 05:46 AM

If this camera was serviced, I would suspect a short in the handle somewhere.

If not, it may be a problem with the microphone noise reduction feature.

John.

Edwin Rutsch · May 18th, 2009, 05:56 PM

I checked with a friend that has the pd150 and you can hear the background white noise, but there is no Brrrrrrrrrt sound.

Then, I just checked when I bought the pd170. it was
03/21/2005

I then pulled out a tape from a couple months after that, and can you believe it. It had the same sound. It wasn't as bad, it is more even in the wave form hidden in the background noise.. Now it has those higher plateaus.

So it looks to me like the camera came with that defect. I just never noticed it since it's hidden in the back ground and I never upped the db levels that much. It's just gotten worse over time.

John Peterson · May 19th, 2009, 07:32 PM

I have to admit, the wave form and the brrrrrrrrrttt ------ brrrrrrrrrttt - sound you describe reminds me an awful lot of the noise from cell phone interference as it looks for a signal.

Any chance of that?

Also, can you turn off the mic noise reduction?

John

Edwin Rutsch · May 22nd, 2009, 10:17 AM

john

I don't think it's the cell phone.. the sound is consistent and goes back to 2005.

I did try noise reduction on and off with no difference.

since the camera seems to have come with this, I wonder that no one else has this problem.. Back then, 2005 - there was a line noise problem that people wrote about when the LCD window was open.. I wonder if there is some relationship to that problem?

Edwin

May 17th, 2009, 02:31 PM	#1
Edwin Rutsch New Boot Join Date: Oct 2007 Location: El Cerito, CA Posts: 10	PD170 Line noise when no mic connected I was dealing with some audio problems with my pd170. I noticed that when there is no mic connected to either inputs and I turn up the levels to 100%, that I hear line noise. you can see the wave form here. pd170 audio problem wave form when there is no Mic connected to input 1 or input 2, Levels turned up above 60% and the levels are turned up high, above 60 or 70%, then there is a background noise in the ear phones and on the tape audio. first part wave from below is level up high, about 100%, someone told me there is always pre amp noise, but is this normal? with level around 50% I don't hear the line noise but if I tape and import the clip, then up the gain 20 db or so, I see the line noise. in both cases you can see background noise. Below is is the wave form expanded way up. on the line is a periodic brrrrrrrrrttt ------ brrrrrrrrrttt - sound I saw there was old problem with line noise on pd170 when opening the flipout lcd, but this audio noise happens all the time. Problem 2 - Sennheiser K6 and ME 64 the other problem I have is with a Sennheiser K6 and ME 64 there's a loud hum. when I replace the k6 modual with another one it goes away. thanks for any help on this. edwin

May 18th, 2009, 05:56 PM	#3
Edwin Rutsch New Boot Join Date: Oct 2007 Location: El Cerito, CA Posts: 10	the camera came with that defect. I checked with a friend that has the pd150 and you can hear the background white noise, but there is no Brrrrrrrrrt sound. Then, I just checked when I bought the pd170. it was 03/21/2005 I then pulled out a tape from a couple months after that, and can you believe it. It had the same sound. It wasn't as bad, it is more even in the wave form hidden in the background noise.. Now it has those higher plateaus. So it looks to me like the camera came with that defect. I just never noticed it since it's hidden in the back ground and I never upped the db levels that much. It's just gotten worse over time. Last edited by Edwin Rutsch; May 18th, 2009 at 05:57 PM. Reason: update spelling

May 22nd, 2009, 10:17 AM	#5
Edwin Rutsch New Boot Join Date: Oct 2007 Location: El Cerito, CA Posts: 10	Cell and Noise reduction john I don't think it's the cell phone.. the sound is consistent and goes back to 2005. I did try noise reduction on and off with no difference. since the camera seems to have come with this, I wonder that no one else has this problem.. Back then, 2005 - there was a line noise problem that people wrote about when the LCD window was open.. I wonder if there is some relationship to that problem? Edwin

May 18th, 2009, 05:46 AM	#2
John Peterson Major Player Join Date: Jun 2008 Location: Monroe, NY Posts: 703	If this camera was serviced, I would suspect a short in the handle somewhere. If not, it may be a problem with the microphone noise reduction feature. John.

May 19th, 2009, 07:32 PM	#4
John Peterson Major Player Join Date: Jun 2008 Location: Monroe, NY Posts: 703	I have to admit, the wave form and the brrrrrrrrrttt ------ brrrrrrrrrttt - sound you describe reminds me an awful lot of the noise from cell phone interference as it looks for a signal. Any chance of that? Also, can you turn off the mic noise reduction? John