Short answer:
The pedalSHIELD was designed to handle electric guitar signals, it could also handle line level signals, but depends on the particular voltage level of this signals (if they are too big the shield will be overloaded).
"The exact definition of line level signals for consumer audio is hard to pin down--different manufacturers adhere to slightly different standards, sometimes even within their own product line. But the Line Level voltage for consumer audio is pretty much defined as a maximum signal voltage of around 5-6 volts. Measure the output of your typical CD player or Tape Player component and you will see maximum voltages in that range." (
extracted from beavisaudio)
In theory:
- Equipment is generally referred to as +4dBu (
3.4Vpp) equipment (professional) or –10dBV (
0.9Vpp) equipment (consumer)
In practice:
- Microphones and passive electric guitars = very tiny signal size
- Keyboards and consumer recording gear = small line level
- Pro recording gear = large line level
In pedalSHIELD:
I would try to explain it as easy as possible: Arduino DUE analog to digital converters work with signals fom 0 to 3.3V (3.3Vpp). pedalSHIELD has an
input stage which can amplify the guitar signal from 1 to 20 times. So with the RV1 on-board trimmer you can adjust this input stage gain.
- Guitar signals go from lets say 0,2Vpp up to 2Vpp (depending on the pickups) so with the RV1 you can amplify the signal close to 3.3Vpp optimizing the ADC range.
- Consumer line level signals go from 0,3 to 2 Vpp, this range is not far from the guitar signal levels, so it should work (I cannot guarantee it cause I dont have any line level device around).
note:
Signal level in dBu = 20 x log (signal voltage / 0.775)
Signal level in dBV = 20 x log (signal voltage)
