Up to the middle of the 20th century, the only available strings for guitar were gut strings for Trebles and silk wound strings for basses: their acoustical performance was different from that of modern Guitar- setup. The salient characteristics of the past setups were: a marked tonal presence, response and brightness typical of the top gut string (certainly superior to plain nylon and in some respects closer to fluocarbon strings) while the basses, on the other hand, possessed an exquisitely vocal quality, i.e. not so bright as, and with less sustain than, modern wound on nylon strings and more fundamental heavy. Our Ambra set was developed in order to best re-create, by means of modern synthetic materials, a different feel. This set was conceived for one grade of tension and consists of -gut coloured Super Nylgut® for Trebles, while for the basses (silvered copper wires wound on Nylgut® multifilament core) we employed a different balance between wire and core in order to obtain warm and deep performances