Before approximately 1660, the lower strings in both plucked and bowed musical instruments were made in pure gut.

Up to this date there are two theories on this: the first believes that the gut strings were twisted in imitation of ropes used in the navy (increase in elasticity), while the second believes that the gut used for the basses was loaded using tanning techniques and then twisted.

We support this second option, that led us to produce the C type loaded gut strings, the production of which is currently still suspended.

Therefore, to solve this inconvenience, we designed the CD and CDL synthetic loaded strings (suitable only for plucked instruments).

CD strings

The CD type strings are synthetic strings used on the lower and medium basses on Lute and Baroque Guitar, characterized by a high standardized specific weight, achieved by loading  the synthetic material with metallic copper powder during the extrusion phase.

The surface is similar to the one of a rectified natural gut. The strings have a percussive and vocal tone, however their sound is full and blends perfectly with the paired string in octave. The working tensions remain unchanged compared to the usual playing habits.

The strings have an excellent tuning stability; they replace the modern wound strings that are too bright to fit the real nature of the Lute.

The CD type strings are also recommended for basses on short double-necks (like the  Liuti attiorbati or Archlutes, and the Swan Neck Lutes in minor D with max length = 105 cm)

The CD diameters thinner than 115 cm have only been partially loaded, in order to work best on the 5^th course of the Lute and the 4^th and 5^th courses of the Baroque Guitar.

CDL strings

These type of strings are partially loaded basses with a length of 150 cm, specifically designed for basses with diapasons between 115 and 135 cm; an example are the historical Archlutes and the non-historical Theorbos with medium and short diapasons (suitable for travelling, and more common nowadays).

This is our answer to the inappropriate use of wound strings as basses on these types of instruments.

We restricted the length to 150 cm in order to avoid the use of such strings as basses on historical Theorbos (the correct strings for these intruments are gut strings or the synthetic NGE strings).

Please note: the human ear has a poor sensibility to the lower frequencies, so that on short distances one might think that these kind of strings will not have a sufficient acoustic energy as compared to wound strings that are perceived as more brilliant thanks to their harmonic richness (see the ‘Phon curves’). However the science of Phonometry shows that the lower frequencies are not dampened by long distances or sound-absorbing elements such as people, chairs or curtains. On the other hand, higher frequencies are greatly absorbed. As a result, a Theorbo using wound strings will not perform well on distances or sound-absorbing elements, while our CDL type basses will still sound great.

The correct installation

Both CD and CDL types are made with a synthetic elastomer that is characterized by the fact that it does not slide (that’s why elastomers are used for the soles of shoes). This implies that the common installing procedure does not work as expected, and might lead to unexpected breakages of the string: as a matter of fact, the poor sliding of the material  leads to a higher tension in the portion between peg and nut as compared to the tension between nut and bridge.

The CD type is very resistant in itself: just as an example, a 145CD string will break to a linear traction of 12 kg.

The correct procedure expects that the string, once fixed on the peg, must be kept constantly out of the nut groove during the whole initial tuning process, and it must be put back in the groove only once it has been pulled by hands and tuned up to the desired note.

This way the tension between peg and nut is the same as the one between nut and bridge, granting a high tuning stability and absence of breakages.

Using lubricants/graphite on the grooves of the nut has not proved to give appreciable benefits.

On this type of strings, there have been a few reports of the following problems:

1. episodes of breakages on gauges 36-46 NNG
   
2. NNG chanterelles (36-46 NNG) have less ‘silvering’ sounds compared to those made with gut
   
3. the thicker NNG strings have more sound in itself as compared to those in gut, but they can’t substitute the wound strings on certain positions (5^th course in Reinessance Lutes, lower octaves, 6^th and 7^th of theorbos of big dimensions)

In order to successfully resolve the above-mentioned issues 1 and 2, instead of using pure Nylgut, we introduced a new blend of Nylgut with a low percentage of our Sugar polymer, that produces a sound closer to gut, providing at the same time an increase in the strength of the string.

In gauges greater than 79 NNG instead – see above point 3 – the Nylgut has been replaced with our bioplastic called Sugar, that has the same specific weight and color of Nylgut. Thanks to this replacement, the sound has greatly improved, becoming comparable with aluminium wound strings. This improvement has been extended up to the 112 NNG.

It should be noted that Sugar allows better acoustic performances also compared to the CD strings, in gauges from 75 CD to 110 CD.

Comparative tests showed that CD strings, even if they are made with Nylgut loaded with metals, have a rounder sound compared to an NNG with equivalent gauge.