Electric Violin - Pickups

Pickups

Electric violins commonly use either magnetic or piezoelectric pickups. Guitar /coil type magnetic pickups require the use of violin strings that have ferrous (iron-containing, as in steel) metal wraps or cores. A few single-coil guitar-style magnetic systems are available, The small body size and arced string arrangement of a violin limit the amount of space available for coil placement. One unusual acoustic/electric violin system uses the string itself as a linear active pickup element. Made to fit standard acoustic violins, the only requisite is that the string is electrically conducting, so the common synthetic or steel core strings can be used.

Generally, piezoelectric pickups are inexpensive and more common. Piezo elements come in the shape of ceramic discs, cylinders or a plastic film. They detect physical vibrations directly, sometimes placed in or on the body, or in some cases actual string vibrations directly, but more commonly general bridge vibrations are sensed. Some piezo setups have a separate pickup (or two, or even four in the case of some Barbera Transducer Systems pickups) within the bridge under each string. A few systems use transducers oriented in various directions to differentiate between bowed and plucked string motion. Operating a switch then selects the preferred mode.

Piezo pickups have a high (capacitive) output impedance, and must be plugged into a high impedance input stage in the amplifier or a powered preamp (a charge amplifier is best). This buffers the signal to avoid low frequency loss and microphonic noise pickup in the instrument cable. Preamplification is often done by an external signal processor, but some electric violin body designs provide internal housing for preamp circuitry.