Sound Grabber II & "Plug In Power"

1 reply to this topic

#1 Jelles

  • Members
  • 1 posts

Posted 13 November 2005 - 05:24 AM

When I record from my Sound Grabber II to my Sony MZ-R91 minidisc recorder using the Mic input, which has "Plug in power", there is lots of distortion at higher volumes. I think the signal might be too strong, because reducing the record level manually in the minidisc recorder has no effect on the distortion.

Is it possible to use the Sound Grabber II to record to my Minidisc recorder, using the "Plug in power" mic input, in such a way that there will be not distortion?For example: without the AAA battery, but using the "Plug in power" from the minidisc recorder?
Or is there something else I should try?

#2 brubart


    Power User

  • Members
  • PipPipPipPipPip
  • 52 posts

Posted 14 November 2005 - 02:16 PM

The distortion could be from several causes:

1. The SPL of the sound you are recording is greater than 120 dB at the boundary surface. That's the maximum SPL the Sound Grabber can accept without distortion.

2. The signal level of the Sound Grabber is so high that it is overloading the MiniDisc mic input. This is a likely cause if your record-level control is set less than about 1/3 up from minimum.

3. The Sound Grabber is receiving DC on its audio lead (the phone-plug tip terminal) from the MiniDisc mic jack.

A possible solution for #2 and #3 is shown in the attached drawing of a simple circuit. The two resistors form a 20 dB pad, which prevents overload of the MiniDisc mic input. The capacitor blocks DC from the MiniDisc phone jack.

If your MiniDisc mic jack is mono, use a mono phone plug. If it's stereo, use a stereo phone plug.

Also, try using a 6-volt N cell in the Sound Grabber in place of the AAA battery. You'll get a little higher SPL without distortion. Fill the gaps around the N cell with bunched-up aluminum foil.

Hope this helps,

Bruce Bartlett
Crown Microphone Engineering

Attached Files