What are typical maximum output levels of acoustic guitar pickups? I have heard the signal levels can be excessive and therefore not compatible with the inputs on wireless transmitters.
The following information came from an article in "Acoustic Guitar" magazine, July 2007. The article was entitled "Electric Round" and focused on the amplification of acoustic guitars.
Rick Turner of D-TAR/Seymour Duncan: As an experiment, we dropped a small ball bearing directly onto our pickup and saw (an output signal) of 100 volts [+40dbV]. I believe that when using a heavy pick, the output level will be between 12 to 14 volts [+22 dbV].
Larry Fishman of Fishman Transducers: From our gear, I see an output level of about 3 volts [+9 dBV].
Udo Rosner of AER: We go up to 44 volts [+33 dBV].
Note: It was not clear from the article if the above output levels were measured at the output of the pickup or at the output of the pickup preamp.
As a point of comparison, a typical output signal from a microphone is 0.001 volt [-60 dBV]. A wireless bodypack transmitter is designed to handle this tiny signal. The guitar pickups had maximum output levels that are 70 to 100 dB greater! Therefore, a typical acoustic guitar pickup must be heavily attenuated before it will work properly with a typical bodypack transmitter. Without adequate attenuation, the pickup signal will easily overload the audio input of the wireless transmitter.