I am trying to create an Arduino based music synthesizer. How can I safely generate line level output (+/- 2 volts centered at zero, with a frequency range from 20Hz-20KHz) from my Arduino using a minimal number of components? This is what I imagine the flow will look like, but please correct me if this is wrong.
- Generate a sine wave tone using a DAC (I'm doing this already using MCP4725)
Level shift the signal -2.5 volts and lower gain
To perform level shifting I think I need to generate a negative 5 volts to supply to a dual supply op amp, but I'm not sure if this is correct
There is a lot of confusing/mixed information on line level requirements. I hooked up the output jack of my macbook pro to an oscilloscope and generated a square wave. It looks like the macbook pro puts out -2 to 2 volts, so I think this is where my target output voltage should be.
Edit: My target output voltage is 1.25VRMS, since I am using a QSC PLX3602 amplifier with an input sensitivity of 1.25VRMS.
- How many milliamps do I need to be able to source for line level
- Given that I am going to be outputting square waves (which can sometimes damage speakers), is there anything I should keep in mind? I am planning on matching my amplifiers RMS wattage rating with the speakers RMS rating. Do square waves produce higher current than RMS?
- Can anyone recommend a schematic or components I can use to accomplish the signal conditioning needed to do this safely/without damaging audio equipment?