Hi

Looking for a bit of help on what I hope is some basic audio electronics.

I'm using a Teensy 4 with a WM8731 Codec (datasheet) in a custom effect unit.

I'm using the line level out to patch back into a mixing desk and finding I alway have to add additional gain at the mixer.

Reading up I see that there are two different line levels, as below from here and wikipedia - Pro line level and Consumer line level and that the WM8731 outputs at Consumer line level.

I'd like to use the unit directly with my mixer without adding gain on the mixer.

The question is what would i need to do to amplify the line out lifting it from consumer level to pro level (single ended is fine)?
- I'm assuming some sort of simple opamp circuit would do it?
- Struggling to get my head around the different units of measure - what gain would I need to achieve a 12dB boost to get it to pro line level?
- Would the supply voltage be a limitation ? I have nice clean 3.3v on the board but could also provide 5v if needed
- How would I match impedance at input end (~10k?) and achieve a low impedance output (~100 Ohm?)

Any input appreciated, Cheer, Paul


'There are two types of line level: +4dBu "Pro" Line Level or -10 dBV "Consumer" line level.
The normal level of the audio signal in a professional studio is +4 dBu or about 1.23 volts (0 dBu=.775 volts).
The level of the audio signal in home stereo equipment, inexpensive "semi-pro" gear is -10 dBV or .316 volts (0dBV=1 volt). This lower "line level" is about 12 dB lower than professional line level.'