For any given size, of many existing violas, a difference of the relative string lengths is often apparent. This causes considerable variability in the actual playing size and feel of violas that are of a similar body length.
Note on variants of string length.
One of the most important considerations when designing an instrument is its string length. This has a direct bearing to the response of the body to the input from the vibrating strings. A simple rule of thumb is the longer the string length the more tension is required to bring it up to pitch; this translates directly to the amount of downward force exerted on the body of the instrument. If this force is too great the body is 'locked down' and there are difficulties achieving a response to the players input, conversely, if the downward force is too weak then the response of the body suffers accordingly. My work with violas over the years has suggested a dimension for a string length that is balanced with the mechanics of the body, and that this proportion may be applied over the entire size range, from the smallest to the largest. This is why proportion is so critical to the violas construction.
A classic mistake present in many violas is where the string length has been adjusted out of proportion to a given body size, either by lengthening the neck of smaller instruments, or shortening those of larger, to make them 'more responsive' or 'easier to play', the result often compromises the violas true potential.
Further fine tuning of the string tension, in order to balance the response from a particular viola, may be achieved by experimenting with the currently available array of highly developed strings, all offering different specific qualities. It should be appreciated that, due to the variants of design and construction of string instruments, although one particular string may be ideal for one instrument, it could also be disastrous for another. Many high tension strings, particularly the violas A string have been developed to overcome the difficulties of violas that have been made in, shall we say, a very rigid fashion, so beware of higher tension strings on a more responsive instrument, you may just lock everything down.
Viola specification - Body size & String Length
The size of a viola is naturally of primary importance for the player. However, it is not the body length alone that needs to be considered.
For any one given size of viola, often a difference may be observed between the relative string lengths of each. This inconsistency can cause two violas of a similar body length to feel very different indeed.
This variability is a result of differences in the design and set up. I have always maintained, the ratio of the stop length, [the distance from the middle of the f holes where the bridge is placed to the upper edge of the viola at the neck root], to the neck length, [the distance from the same upper edge of the viola to the nut position that marks the limit of the vibrating string], should always be at a ratio of 3:2 This also being the situation with the violin.
Although the use of this ratio is relatively recent, it is one that has been accepted by players and makers over the past century or more, and if ignored can cause many difficult intonation problems. Unfortunately, many viola set ups do not adhere to this fundamental ratio, resulting in a wide variation of final string lengths for any one particular body size. This is often the case with many older instruments which, over the years, may have been changed considerably from their original dimensions.
To enable players to compare the characteristics of viola set ups with my own instruments I have included here the essential relative dimensions of string length to body length.
One of the aims in establishing my own workshop pattern is so that within this group of instruments, an incremental increase of the body length becomes naturally associated with a relative increase in the string length. The string length adopted for each of my violas is, as a result, in very good balance with its relative body size, thereby giving an exceptional dynamically balanced instrument.
The point at which the string
leaves the nut
The point where the string
crosses the bridge
This size chart may be useful to players making dimensional comparisons between my violas and other violas of the same body length.