Hey, if the client has a defective pickup and the cost is $100, that's okay but I don't want to spend 100 dollars of the client's money on a guess. The $2 piezos work great but it is rare to find them on ebay in the narrow width format (3/32 / 2.3mm) leading to the necessity of paying around $100 for a narrow format pickup from Fishman.

Over the years I've purchased quite a few piezo pickups on ebay at dirt cheap prices in lots with a single unit cost of about $2 and have accumulated a wide range of sizes and thicknesses. I have personally accidentally damaged a piezo while rushing during a saddle height adjustment resulting in this noise problem and have successfully addressed this problem on at least two other occasions by replacing the piezo. The current replacement from Fishman is called the AG Series. The ones that I've had problems with are the very plain rigid strip that looks like it has a thin covering of foil and a typical example is the Martin Thinline. There are a number of piezo formats ranging from the simple piezo cable which is just a thin coaxial wire with the insulator made of piezo material to a number of other sandwich styles. The fact that there is what seems to be ground problem and the noise is impacted by touching a finger to the backshell of the instrument cable causes me to not be so confident.įor clarification. But I have had instances where the cause has been a defective undersaddle piezo pickup.

Sometimes its just a dirty/defective or miswired output jack and that is my first thought. The symptoms are excessive noise at higher signal levels and noise interrupt when you touch the metal backshell of the instrument cable and, the pickup is still actually functioning with a strong output (its understood that the cable and the amplifier has been ruled out). These could be any typical manufactured acoustic with an undersaddle piezo and active preamp. Every once in a while I'll get in an acoustic guitar that has what presents itself as a ground hum problem.

Guitar piezo preamp