Sound Hum-Projector to Camera to Monitor

[Barry Azusa]

In an effort to transfer sound from my Super 8 projector to the computer (with the TV monitor)I'm getting a hum on the monitor (and probably the hard drive). I'm running from the projector's "aux out" (headphone) to a Sony PD-150 camera mic input set to "line." From the camera's "video/audio" it's the RCA connectors to the TV. I can reduce the hum a bit by lowering the projector's output volume, but hum nonetheless. With the "aux out" plug out, the sound is perfect. And while the unit is in neutral (and the plug out), turning the volume up high there is no hum. Probably some impedance problem. The film transfer aspect of production is new to me, but I suspect (and I hope) some of you pros will see the problem's resolution as a no-brainer. Any assistance would be much appreciated. Barry

[#Pedro]

I?ve got the very same problem, but only when trying to connect the Elmo projector to any video stuff, never with connection to quality audio stuff. Maybe a grounding problem.
You easyly can fix it, buying an cheap audio converter (transformer) at a electronic supplyer. The conversion ratio should be somewhat 1:1 or 1:2, the input impendance (to where you feed the signal) should be as high as possible (1...50 kOhms) and the output impendance (to connect to the video) about 1 kOhm.
The converter is nothing else than a small transformator. This avoids any direct connection between the two devices, not for the signal and not for the ground. For stereo you?ll need two.
I also seen ready connected kits, for 10 time more bucks, at car audio supplyers, in order to connect car radios to external amplifyers.
Pedro

<font color="#a62a2a" size="1">[ June 07, 2002 03:40 AM: Message edited by: #Pedro ]</font>