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-   -   PD170 Noises! (https://www.dvinfo.net/forum/all-things-audio/122912-pd170-noises.html)

Colin Willsher June 2nd, 2008 03:30 AM

PD170 Noises!
 
Hi,

I'm hoping someone can point me in the right direction here. I've had a PD170 for a few years now and I'm sure this problem has been present almost as long but it's getting worse and made life very difficult on the last wedding I edited.

I was getting very occasional, glitchy, electrical interference which was audible in the headphones and unfortunately recording to tape too. I'ts taken me an age to pin it down as it always appeared to have a life of it's own but I've now found it happens when any mechanical operations are being carried out on the camera. This might be simply ejecting a tape (and therefore irrelevant) but the main problem is that it is noticable when zooming or focussing too (whether manually or auto).

Using auto focus is a nightmare because it is constantly correcting every few seconds and the smallest adjustments seem to create the most noise.
The noise is present on both channels and even switching in noise reduction has no effect on this signal.

Has anyone else experienced this and do you think it can be fixed? (Hopefully without sending it to mainland europe!).

Ty Ford June 2nd, 2008 06:53 AM

Hello Colin,

A lot of cameras mechanically conducts their motor noises to the attached microphone.

Maybe:

1. They were there all along and you have just gotten so into the audio that you're starting to hear them. Maybe you're shooting in quieter locations and can now hear the camera noise.

2. Your shock mount is searing out or some other change in your mic/camera mechanical connection is allowing parts to touch and conduct the mechanical noises you camera makes.

Regards,

Ty Ford

Dan Brockett June 2nd, 2008 08:15 AM

Unfortunately
 
Hi Colin:

I have heard this affliction in a lot of other cameras as well, primarily inexpensive prosumer camcorders. Unfortunately, the PD-170 is considered to be probably the second noisiest and worse sounding camcorder ever sold, the worst being the PD-150. The PD-170 supposedly had audio fixes implemented to fix the audio shortcomings of the PD-150 (there were actually several class action lawsuits filed in the day against Sony for the unusable audio quality of the PD-150). It was interesting that all of the pros that bought the PD-150 and 170 instigated a class action suit while the more compliant and less demanding consumers who bought the VX-2000 and 2100 just basically were left out in the cold as Sony was able to pawn off the incredibly poor audio quality to "it's good enough for a consumer" statement when VX-2000/2100 owners would send their cameras in to fix the unusable audio.

You can try sending it to Sony service or you could try to hunt down and see if there are still any companies doing the complete overhaul of the Sony PD-170 audio circuitry, there used to be a couple of U.K. vendors that basically gutted the audio chain in the PD-150/170 and replaced it with a straight line in circuit that totally bypassed the Sony circuitry, but as I recall, it was an expensive mod.

Sorry to say that it's probably time to step up to the plate and buy a better sounding camcorder, there is no inexpensive, easy way to fix this and it would cost much more than an older PAL DV camcorder is even worth.

Best of luck,

Dan

Ty Ford June 2nd, 2008 08:40 AM

Quote:

Originally Posted by Dan Brockett (Post 887056)
Hi Collin:
The PD-170 supposedly had audio fixes implemented to fix the audio shortcomings of the PD-150 (there were actually several class action lawsuits filed in the day against Sony for the unusable audio quality of the PD-150).
Dan

Thanks Dan,

I didn't know about the lawsuits.

Back then, the forum boards were filled with comments about how great the PD150 and 170 were when they came out. When I tried to point out problems, I was shouted down by "professional videographers" as someone who didn't know what I was talking about.

The on-camera mic on the PD150 was pretty atrocious. I gave an Audio Bootcamp seminar here at my studio and one of the folks showed up with one. When we swapped it out for a Sennheiser 416 and people heard the difference, they almost passed out from the shock.

I did hear about the PD150/170 circuitry mod from the UK, but that's a different problem than hearing motor noise through an onboard mic. I'm guessing that would be a mechanical issue rather than electrical. However, if the motors were spewing electrical noise as they moved and that electrical noise was making its way into the audio. Well, there you are.

Try this. Use a boom mic or a lav that's NOT mechanically attached to the camera. Noise still there? There's your answer.

Regards,

Ty Ford

Don Bloom June 2nd, 2008 10:02 AM

I've been using a 150 for about 7 years and a 170 for about 2. Here's what I found.
Yep, the 150 is worse than the 170 and they both suck with the stock mic. If I use my AT897 on either the noise is somewhat less not much but a tiny bit. If I'm using my AKG300/CK93 there is a definate hum thru the camera.

Ty, as for checking where it's coming from, when I use strictly wireless to the camera, no hum at all. In any case it's not really that hard to NR it out. AAMOF I have a preset in my NR to do that right from the git go.
Funny thing I've used the stock mount, a CAC12 and even mounted a shock mount. That obviously works the best. The 250 didn't have any noise and the old VX1000 worked great.
Ah well, technology advances huh? :-)

Don

Colin Willsher June 3rd, 2008 01:17 PM

Thanks guys, sorry for the slow response.

Just to confirm this is not noise coming into the mics per se, but some sort of electrical interference making it's way onto tape when I operate any focussing or zoom controls. This is present even when no mics are attached and phantom power is switched off etc. Doesn't matter if I switch to line input or switch in the onboard NR. And it's a really quite nasty sound now - rather like you might get from a really dirty pot on an analogue mixing desk.

Anyway, I've tracked down a local technician who thinks he knows what the problem might be - my fingers are well and truly crossed and I'll keep you all posted.

Ty Ford June 3rd, 2008 04:53 PM

Colin,

Operating any audio circuit with no mics or line level sources plugged in terminates the connection improperly and is guaranteed to gather noise.

A better test is to attach mics by a cable at least 6 feet long and place them away from the camera. Then put the camera in record and test the recording for motor noises.

Regards,

Ty Ford

Colin Willsher July 6th, 2008 03:35 AM

Sorry, forgot to post the solution to this, for anyone that's interested.

It turned out to be a blown capacitor - all fixed now and quieter than ever! ;o)

Ty Ford July 6th, 2008 03:42 AM

where was it?

Ty Ford

Douglas Toltzman July 6th, 2008 12:57 PM

Since I build balance pre-amps, based on the description of the problem, I'm guessing the blown capacitor was inline with the power supply to the pre-amp circuit. Any electrical noise from motors, switching transistors, resistors, etc. will propagate throughout the camera if not filtered by noise filtering capacitors. Essentially, the cap shorts the signal noise to ground. Without it, all that noise just feeds right into the I.C. that is amplifying the input signal.

Colin Willsher July 6th, 2008 04:53 PM

Sounds about right Douglas. I had a local video repair chap fix it for me - he had suspected the motor itself at first but ruled that out.

I was pretty fortunate, in that I didn't have to send it to the Sony service centre in mainland Europe, which would have cost me as much as this guy charged just to get it there - it was well out of warranty anyway so worth a punt.


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