Mic & Line Levels
Line Level
- Nominal level of around 1 volt
- 1 volt = +4 dBu (0.775 V reference)
Mic Level
- Mic outputs are normally quite low; around a millivolt (1 mV)
- Around 60 dB lower than line level
- Microphone preamplifiers have a gain control to provide amplification between 30 and 80 dB
Consumer Sources
- Lower output levels than line level; around 100 mV
- 100 mV = -10dBu
- Line level amplifiers can be used to bring such signals up to line level, as well as balancing the unbalanced output
DI (Direct Injection) Boxes
- Converts an instrument's output to a low impedance balanced signal
- The signal's output is reduced to mic level
- The low impedance balanced mic level signal appears on a standard XLR output
- There is also an output jack for the unprocessed signal to pass to an amplifier
© Matt Bellingham 2003 – 2006
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License.
