MagicVOX  USB Headset Adaptor
Audio Interface Characteristics

 

NOTES -
  • Mic Input
  • Headphone Output
  • USB connector
  • Microsoft Volume Control (mixer)
  • Volume Control Slider Position Definition:

mswSlider.gif (2690 bytes)

  • Except as noted, all measurements were made at 1KHz and with Sliders set to Middle.
  • Ref:  0.001V = 0 dBmV;  0.010V = 20 dBmV;  0.100V = 40 dBmV.
  • All measurements were made on the Left Channel.  A spot check of the Right Channel showed virtually identical results.

 

Mic  MICROPHONE Input -Min Input Schematic
  • Mic Input Z:
  • 960 ohms @ 20Hz
  • 945 ohms @ 1KHz
  • 311 ohms @ 20KHz
  • Mic Bias:
  • 1440 ohm to +3.1V
  • Advanced Controls:
  • None
  • Mic Input Connector:
  • 1/8 inch (3.5mm) stereo phone jack
  • Tip contact is Mic Input w/ +3.1V bias
  • Ring contact has no connection
  • Sleeve contact is ground
  • The Mic Input jack is marked:   Mic
  • Clipping:  Input Level for clipping vs. Microphone Slider Position
  • Speaker Slider = Middle
MVox-MicClip.gif (2845 bytes)
  • Levels:  Headphone Output Level vs. Microphone Slider Position
  • 10mV (20dBmV) Mic input
  • Speaker Slider = Middle
MVox-MicSlider.gif (2831 bytes)
Headphone  HEADPHONE OUTPUT-Line Output Schematic
  • Headphone Output Source Z:  25 ohms
  • Clipping:  380mV (+ 51.6 dBmV) output
  • Headphone Output Connector:
  • 1/8 inch (3.5mm) stereo phone jack
  • Tip contact is Left Headphone Output
  • Ring contact is Right Headphone Output
  • Sleeve contact is ground
  • The Headphone Output jack is marked:  Headphone
  • Levels:  Headphone Output vs. Speaker Slider Position
  • 10mV (20dBmV) Mic input
  • Mic Slider = Middle

 

 
Lynn Ashley

8 August 2003