Frequently asked questions
What is Nylgut?
Nylgut is a synthetic material invented, copyrighted, and patented, by Aquila Corde Armoniche in 1997: it has the same mean specific weight as gut and a low degree of humidity absorption – ony 10% that of nylon.
It possesses a sonic profile almost identical to natural gut, unlike Nylon, whose sonic profile is quite different than natural gut.
In theory one should use a gut string and a Nylgut string of the same diameter.
But since nylgut has a slightly higher stretch factor than gut we advise using the next gauge higher.
When tuning it for the first time, carefully and repeatedly pull the string with your fingers while tightening it. It is a good idea to help the chanterelle over the nut, to avoid extra friction on the small diameter string.
Nylgut strings cannot be used on bowed instruments.
What is Breaking Point Index?
The Breaking Point Index is the highest frequency a gut string of any diameter can reach at a string length of 1mt. For gut a mean value of 260 Hz.mt is a good reference parameter. For Nylgut, one can generally go as far as 300 Hz/meter. In other words, a 1 meter long gut string will statistically always break at 260 Hz, i.e. about ‘C’. Hence we deduce that the product of the pitch of the treble and by the string length (‘Working Index’) must always be below this value, and it is strongly advised to keep the number below 240. Instruments of the gut string era were always designed to function within these boundaries, and is why instrument families are scaled the way they are, and why re-entrant tunings were used on some instruments.
What is the use of this in practice?
A safe index for gut stringing should not exceed the 240 value. For Nylgut, ~260.
Example I: can I tune a gut strung lute top string to A, with a string length of 62cm in the pitch center of A 440 ?
.62 mt (62cm) x 440 (Hz) = 272.8 Hz.mt
The answer is: no, I can’t.
What should the appropriate string length be? A safe index should not exceed the 240 value. 240/440 Hz = .545 mt, so in practice the appropriate string length (at A-440) should not exceed 54 cm.
Example II: can I tune a gut strung lute in G, with a string length of 62cm in the pitch center of A 440 of .62 mt? (62cm) x 392 (Hz) = 243 Hz.mtThe answer is: yes, I can, most definitely if using NNG.
The rule of thumb is, assuming the contact points are free from any sharp edges, which will quickly sever a gut or Nylgut string: Keep the working index below 240 for gut, 260 for NNG, is the recommended upper limit.
Gut at working index between 250 and 260: not safe. The treble could break in a few hours/days, especially in high humidity conditions.
Gut at working index over 260. Extreme danger; the treble will break immediately or within minutes.
Because of the lack of the instrument size standardization, it is important to verify whether medieval lutes and harps adhere to these values. Historical instruments or copies that, when calculated, divulge numbers that are above 260, were not intended by the maker to be tuned to the pitch center being calculated.
Can Nylgut be bowed?
Sorry, no. Nylgut is only suitable for plucked instruments.
For what pitch center are your gauging recommendations?
All recommendations for all instruments are at 415hz =a'.
How do I convert Pirastro/Dlugolecki numbers to Aquila?
Aquila numbers are metric, just lacking a decimal point. Therefore a 60HU is a 0.60mm string.
To convert Pirastro/Dlugolecki numbers to metric, multiply by 5.
For example, a 12 in their system is a 60 in metric. (5x12)
Why is your medium gauge recommendation different than some other brands?
Every maker has their own idea about what constitutes light, medium, or heavy gauge. The reality is that these descriptions are only a starting place to determine what your instrument actually wants in terms of tension, no matter which maker you purchase strings from.
If you are happy with the gauging from a different maker and want to try Aquila gut strings, order the same gauges in Aquila strings because they will produce the same tension as what you are currently using.
This applies only to plain strings. For wound strings, one needs to pair the Aquila light, medium, or heavy with the corresponding gauge recommendation for Aquila plain strings .
How do I convert Nylon numbers to Nylgut?
Nylon has less density than Nylgut, so you cannot order the same gauges in Nylgut as you are using with Nylon. If your Nylon numbers are metric, a pretty reliable method is to order Nylgut one gauge lighter, but it's better to use a calculator, of which there are several to be found online.
If your Nylon numbers are in inches, multiply by 2.54 to get the metric equivalent. If you have questions, don't hesitate to contact us.
Should I pre-tension my gut strings?
In the case of violin e'', definitely. This was common practice in the 18th century. The violin e'' is the most highly tensioned string on any instrument and to achieve maximum life, should never be brought immediately to pitch right out of the package. There are several ways to do this; a spare violin, your usual violin, or a small tensioning rack (which we will be selling soon) is all that's needed.
Bring the string slowly up to around 3 semitones low of intended pitch and leave it overnight. Then you will have a string ready to use when you need it.
A good practice for installing any new gut string, except the largest, is in the evening to bring the string slowly up to 3 semitones low, leave it overnight, and finish tensioning in the morning.