cunninghamprod
New member
Problem: mechanical noise/hum when XLR audio cables attached to HVX 200 when an AC powered Panasonic LH900 LCD is hooked into component out.
The physical set up:
Battery powered HVX200 with XLR to audio input – mic level set
Component out of HVX200 to Panasonic LH900 monitor, power supplied by NRG or Aspen.
If you plug in an XLR cable (especially if you hold the connector) you hear a mechanical noise/hum.
If you just plug the mics into the XLR on the camera no noise (or the noise is so low as not to be noticed). I tried this with 4 different XLR cables with the same result.
If you power the camera with AC & the monitor with AC from same outlet same noise.
If you power the monitor with DC, no noise.
BTW I connected the mics with same cables via a Lectrosonic wireless system with no noise.
Since I tried powering the monitor with two different AC power supplies and got the same results, my guess is a problem in the shielding in the LH900 and/or the HVX (or both). As far as I know Panasonic does not offer an AC power supply for the LH900 (odd that a $4,000 monitor doesn’t come with a plug), so I don’t know whether that might solve this problem.
Also, just for grins I plugged the camera composite out to the LH900 video in and there was no hum. However, when I touched the XLR connector there was a tiny click and a slight increase in white noise.
So, major spotlight on the component cable system, and still a shielding problem.
Gary Adcock suggested that I attach the ferrous core that usually goes on the fire wire cables, I haven’t tried that yet. Also, it was suggested that I try lifting the ground (3 to two plug), that had no effect.
Any thoughts or suggestions would be appreciated.
Cheers,
The physical set up:
Battery powered HVX200 with XLR to audio input – mic level set
Component out of HVX200 to Panasonic LH900 monitor, power supplied by NRG or Aspen.
If you plug in an XLR cable (especially if you hold the connector) you hear a mechanical noise/hum.
If you just plug the mics into the XLR on the camera no noise (or the noise is so low as not to be noticed). I tried this with 4 different XLR cables with the same result.
If you power the camera with AC & the monitor with AC from same outlet same noise.
If you power the monitor with DC, no noise.
BTW I connected the mics with same cables via a Lectrosonic wireless system with no noise.
Since I tried powering the monitor with two different AC power supplies and got the same results, my guess is a problem in the shielding in the LH900 and/or the HVX (or both). As far as I know Panasonic does not offer an AC power supply for the LH900 (odd that a $4,000 monitor doesn’t come with a plug), so I don’t know whether that might solve this problem.
Also, just for grins I plugged the camera composite out to the LH900 video in and there was no hum. However, when I touched the XLR connector there was a tiny click and a slight increase in white noise.
So, major spotlight on the component cable system, and still a shielding problem.
Gary Adcock suggested that I attach the ferrous core that usually goes on the fire wire cables, I haven’t tried that yet. Also, it was suggested that I try lifting the ground (3 to two plug), that had no effect.
Any thoughts or suggestions would be appreciated.
Cheers,