Attenuating audio cord?

[painless]

I am trying to record pilot/pax audio while videoing flights. It is my understanding that you need to use an attenuating audio chord if you take the audio off of the pax headset jack.

I have an adapter I got from Marv Golden that allows me to plug into the pax headset jack and then into my video camera. It also has a y adapter to allow the pax to plug his/her headset in. The plug that goes into the camera is stereo. When I use this setup, I get slightly distorted audio, thus the need for the attenuating chord.

So off to Radio Shack I go and I can only find a mono attenuating chord. My plan is to use a stereo/mono connector to connect the stereo plug from the Marv Golden rig into the mono attenuating chord. Then use a mono to stereo adapter to plug into the camera.

Tests with the above have proven unsuccessful. No audio at all. On testing the attenuating chord, I am getting continunity between the center post and side connector. Is this right for an attenuating chord?? Seems wrong to me.

Any help from the audiophyles out there would be appreciated.

[vlittle]

Yes, you should measure some resistance between the tip and sleeve of the plug. It may be different for both ends, depending on how it's made.

The input end (headphone jack) should be the one that has the higher resistance. If it measures the same on both ends, it does not matter.

Hope that helps.

Vern

[rvbuilder2002]

Originally Posted by painless

I am trying to record pilot/pax audio while videoing flights. It is my understanding that you need to use an attenuating audio chord if you take the audio off of the pax headset jack.

I have an adapter I got from Marv Golden that allows me to plug into the pax headset jack and then into my video camera. It also has a y adapter to allow the pax to plug his/her headset in. The plug that goes into the camera is stereo. When I use this setup, I get slightly distorted audio, thus the need for the attenuating chord.

So off to Radio Shack I go and I can only find a mono attenuating chord. My plan is to use a stereo/mono connector to connect the stereo plug from the Marv Golden rig into the mono attenuating chord. Then use a mono to stereo adapter to plug into the camera.

Tests with the above have proven unsuccessful. No audio at all. On testing the attenuating chord, I am getting continunity between the center post and side connector. Is this right for an attenuating chord?? Seems wrong to me.

Any help from the audiophyles out there would be appreciated.

I would avoid adapting from stereo to mono to stereo, etc, using cords and adapters (always seems to induce more problems with all the connections).
If you are solder savvy, you could modify your own cord. Cut each signal line and install a 47K ohm resistor in series on each signal line, and I think you will find it works great.

[painless]

Thanks Scott, I may just do that. The distortion that I have is tolerable, but it would be nice if it were a bit clearer. Music I pipe in via my Ipod would sound better as well.

[zkvii]

Hi,

We have GMA340 'rear passengers - ie. places 3 and 4' audio going to a DV camera - seperate control that way on the volume. But it does need attenuation - I got a 3.5mm back to back cable from the local 'radio shack equiv' , chopped and added a pair of D-pins to the 2 signal lines, while keeping the ground line intact. Then a pair of resistors with D pins crimped can be added. The D-pins makes changing / trying different resistors a lot simpler. I seem to remember we ended up with fairly high resistors in the end, 100K springs to mind.

If you can remove the auto-gain on the DV camera side that will help a lot with the balance.

HTH,

Carl

[rvbuilder2002]

Originally Posted by painless

Thanks Scott, I may just do that. The distortion that I have is tolerable, but it would be nice if it were a bit clearer. Music I pipe in via my Ipod would sound better as well.

I'm not sure if it well help with the Ipod issue but it might if you are needing to keep the volume on the Ipod set very low. Most intercom aux. music audio inputs are designed to receive an audio signal that is typical form the head phone output of music devices. Because of this they are already designed for a much higher signal level.
The reason you need to attenuate the signal level from the intercom output is you are using a headphone signal level (meant to drive a set of head phones) and routing it into a microphone input (a typical mic signal level is minute by comparison too a headphone signal level).