iz8dwf | piezo contact pickup preamplifier first test @iz8dwf | Uploaded March 2015 | Updated October 2024, 56 minutes ago.
A friend asked for a good piezo transducer preamplifier.
This prototype has 2 channels, 12 dB voltage gain and single-ended input to differential output.
THD is less than 0.02% as measured with my HP-339A.
It is battery powered, but a phantom powered version is possible too.
The oscilloscope is configured to show the difference of CH1 and CH2 to visualize the differential signal on the output of the preamplifier.