Roger Williams - Luthier

Fitting the B-Band UST pickup system

First I use a cello-peg reamer to open-up the end-pin hole to 13.5 mm diameter (note the tape which acts as a depth gauge).  If an end-pin hole is not already present then I "spot" the centre and carefully drill a 6mm hole.  I ream this hole with a violin peg reamer until the larger reamer fits and continue until the end jack is a nice push fit.

The BBand UST pickup is a very thin (0.4 mm) sensitive, electret film and relies on good performance and balance for an intimate contact between the bottom of the saddle slot and the saddle. This means that the saddle slot and base of the saddle have to be perfectly flat.  In addition if the saddle is not a perfect sliding fit in the slot and is at all liable to tilt forward then I always recommend a new hand-cut bone saddle often accompanied by a very thin (0.3mm) veneer shim under the transducer for improved balance.

A small hole is drilled at an angle through the bottom of the bridge at both ends of the saddle slot allowing the pickup sensor to be pulled though.  Placing the pickup sensor in a hole at each end of the saddle helps to avoid string balance problems.

The body of the pickup (centre) shows the end-pin jack with pre-amp and the wire to the battery.  The UST pickup (right) has a small push connector which attaches to the preamp before installation.  I usually locate the battery in its little box to the back of the instrument, adjacent to a back brace but out of view from the sound-hole.

New strings are fitted and brought up to tension.  I measure the action at the 12th fret and adjust the final saddle height to obtain the required action.  Then I play it!  If all sounds well then OK, but sometimes an improvement in balance can be obtained by inserting a very thin strip of veneer between the sensor and the saddle.

There you are - all fitted and ready to perform.

The AST (Acoustic Soundboard Transducer) installation follows the same procedure but obviously the attention to the bridge and saddle is unnecessary as the thin-film transducer is stuck to the table under the bridge.

The UST and AST can also be used in combination through a two-channel preamp which allows mixing of the signals for optimum sound and tonal balance.