I frequently use Tram TR-50s with the Sennheiser G2 wireless transmitters.

Yesterday, I was using the Sennheiser 500 Plug-On Transmitters with the Tram TR-50s.

Each Tram TR-50 has a XLR connector with a built in power supply for the lavaliere that can be powered by a small (357/SR44) battery, or powered by 48 volt phantom power.

I had the phantom power on the Plug-On Transmitters set to the off position.

As I was setting up for a shoot, I powered on the transmitters, and I immediately noticed that the microphones were active. This was before I pushed in the battery holder (which then powers the mic with the battery).

Thus, I was not using phantom power nor was I using battery power.

I was amazed that the mic was working. It appeared to sound normal.

So, I double checked to ensure that the phantom power was off, it was.

Then I tested two other TR-50's with two other transmitters. One was another 500 G2 series, and one was a 100 G2 series. Both worked.

The 100 G2 series does not even have phantom power.

I wonder if anyone else has experience this same condition.

I also have G2 500s and TR-50's - I'll run a couple tests tomorrow.

Have you found you need to crank the bodypack transmitter sensitivity to get decent signal out of the TR-50? Mine's usually at 0 or -10 (compared to -20 for the stock ME2 lav).

I think the G2 SK100 transmitter provides a small voltage (1 or 2 volts) to power a lav - maybe this is present at the mic input when phantom power is off and is enough to power the Tram. After all, the battery is not 48 V.

Nick

Dear Mark,

Thank you, it would be nice to see if others are experiencing the same thing.

I usually run at -10db, if I remember correctly. I will check.

Dear Nick,

Yes, that may explain it, depending on the circuit in the Tram power supply.

In any case, it would be very nice to never have to put a battery in the Trams. The battery lasts a long time, but not if it is left on continuously. In many cases, the battery holder is pulled out, but the vibrations from transporting the Tram may cause the battery to engage again, resulting in a dead battery next time. So, the best practice is to remove the battery at the end of the day.

Just to be clear, the Tram TR-50's are wonderful mics that sound great and are provided with great mounting accessories.

Hi Dan,

Sorry I haven't tested that setup for you yet - things have been really busy and will be until early next week. I'll test it out as soon as I have a chance!

Mark

Dear Mark,

Thanks for the update.

I have been real busy also.

I checked my Sennheiser G2 wireless plug-on transmitters sensitivity settings.

I am usually using -10 db sensitivity with the Tram TR-50's. However, the mics are buried under thick Civil War period clothing. On one, where the coat was very thick, I was using 0 db.


I again tested the Tram TR-50's with the 100 and 500 series plug-on transmitters. I wanted to test again after the microphones had been without battery power for a few days to ensure that any residual charge that the microphone had was disipated.

Again the microphones appeared to work fine without battery power (and without Phantom Power being on) when used with the Sennheiser G2 wireless plug-on transmitters.

You could check the transmitters with a voltmeter to see if there is voltage on the pins when the phantom is off. Do the Trams also work when Phantom is on?

Dear Daniel,

Good Idea.

I have not tested them recently with Phantom Power on. When I first purchased them, I believe that I did test them without a battery and Phantom Power on.

I have 3 of the Sennheiser 500 plug-on transmitters. These have Phantom Power and 1 of the 100 series that does not have Phantom Power. All of them worth without a battery in the Tram TR-50.

I will run a test as soon as possible.