hum with trv38 and sebnnn. mke

I'm trying a sennheiser mke300 with my trv38 through the external mic input. it has a loud hum, which isn't like a buzz but a loud steady hum or low frequency noise. A friend had told me the sonys havve a roblem with external mics because of their powered mic inputs. Is it fixable without asdding an xlr adapter or someting like that. i tried a rod videomic which had no hum but it hada pronmounced low end even with low cut filter negaged. also, the rode recorded in stereo whereas the mke300 is in monmo. i had read apost soemwhere confirming that the trv38 and other sonys only have a mono input so audiois only recorded onto the loeft channel, which i found ot be true, butr not withthe Rode. if the mke300 isn't right for this camera, what is a btter suggestion in the $160 range without having to use an xlr adapter (I Could use some kind of inline connector)
Thanks

The 38 has a stereo mic input. They are fairly low noise. With a mic like the AT822, you'll hear no background noise. Some mics will pick up the motor noise from the camcorder. If this happens, you'll need to use a shock mount for it (shock mount is a good idea in all cases anyway).
A mono mic, like the Rode Videomic, will record only to the left channel if it has a mono plug. Some mono mics have a stereo plug and are wired to record the mono signal on both left and right channels.
If you are using a mono mic with a mono plug, the playback sound from the camcorder will usually (but not always) be on both channels if you use the analog outputs from the camcorder. But, you'll only hear it on the left channel if you use the digital output (firewire).