[DR-40] External electret condenser microphone (TSR) ?

[Winfried]

Hello,

Like others, I notice the DR-40 suffers from radio interence when using the internal microphones and the cellphones in the room have a hard time connecting (ie. strong signals).

Before buying an XLR microphone, I notice i have an old Sony electret condenser microphone ECM-MS907 lying around.

Will it work with a DR-40 and solve the RFI issue, and if it's likely, how should I configure the DR-40 to use that microphone? It can be on/off, and when on, record at a 90°/120° angle. FWIW, I only use the DR-40 to record interviews, not live concerts.

Thank you.

 

[tzdvl]

The ECM-MS907 will not work with the DR-40.

The output TRS connector from the Sony mic is configured as two mono signals (Tip = Left positive, Ring = Right positive, and Sleeve =common ground).

The DR-40 can ONLY be used with balanced (hot, cold, ground) mics.

 

[Winfried]

Thank you. It does work, but it's weak, and the on/off button makes no difference.

What affordable (home use, not professional) balanced microphone would you recommend.

 

[tzdvl]

Unfortunately, the engineers who designed the DR-40 apparently intended for it to be used with and connected to "pro" spec equipment. That is, balanced microphones and balanced line inputs only.

There is no way I've found to connect an unbalanced mic or input source to the DR-40 without using an external mixer or a matching transformer. (There have been several threads in this forum discussing this.)

When you connect a "stereo" mic like the Sony, using the TRS "stereo" output plug, the Left and Right positive + mic outputs are connected to the Hot and Cold (+ and -) TRS/XLR input terminals of ONE channel of the DR-40. The two mic signals get mixed together out of phase, so everything is cancelled EXCEPT the "difference" between the two mic signals. You will record a low level signal that sounds "tinny", with poor low frequency response.

The same types of TRS plugs and jacks are used for "L/R/ground" stereo connections, AND for single-channel balanced "Hot/Cold/Ground" connections, but the two systems are not compatible.

So unfortunately, you'll have to get one or two balanced mics to use with the DR-40.

You can set the DR-40 to make a mono recording using a single microphone connected to the L channel input (REC MODE: Mono, SOURCE: EXT IN 1. See pages 44-45 of the Reference Manual).
That's probably how you connected the Sony mic.

If you need a stereo recording, or separate channels for interviewer and interviewee, you'll need two mics.

For a SINGLE mic to record two people, you need something similar to the Mackie EM-91C.
https://www.sweetwater.com/store/detail/EM91C--mackie-em-91c-cardioid-dynamic-vocal-microphone

You want a mic that is designed to pick up general room sound, not a "vocal" type mic with a ball windscreen.
And any similar mic cheaper than $40 or so will sound pretty mediocre.

Anyone else have any suggestions?