Setting up the Hurdy Gurdy . (2)
The trompette is arguably the most problematic area of the Hurdy Gurdy largely because of the wide variations in timbre that can be achieved. The particular sound required will be dictated by the repertoire and the player.
The Trompette string will normally be of gut although nylon can work well for this string. If nylon is used it should not be of the guitar string variety. The reason guitar strings do not bow well is unknown to the writer but trust me, they don’t ! The nylon to use is the monofilament used in fishing ( generally known as "Perlon" ).
The gauge of the string is dependant on many factors. I will assume the string is to be tuned to c’
Once the string is selected, consideration must be given to its alignment. All the articles I have read insist that the string must lie parallel with the top of the instrument. I would qualify this by pointing out that if the wheel is not perpendicular to the soundboard, ( which many are not ) , aligning the string parallel to it has the effect of bowing the string at an angle which is not ideal for rapid articulation. It may be found that moving the string up the Ear will improve sensitivity.
The Tirant should be as light as possible, I use polyester cobblers thread and tie it on using a clove hitch which permits sideways adjustment but prevents unintentional movement. The angle formed at the Tirant junction should be as slight as possible, the lightest tension on the Tirant should be just enough to sound the trompette at the highest playing speed. This will ensure that adjustments to the Tirant peg will not noticeably alter the pitch of the Trompette string. It is usually possible to alter the string anchor point to achieve this.
The tone of the Trompette can be altered by affecting the resonance of the soundboard in the area of the foot. The bridge should be positioned over the lower edge of the soundboard strut but some instruments do not achieve this, resulting in excessive vibration under the foot of the chien. This vibration is then transmitted to the chien to the detriment of tone. A way to overcome this is to attach a mass ( a £1 coin works well) with "Blue Tack" to the soundboard close to the foot of the chien. Inlay of Mother of Pearl under the foot works similarly. To make the sound crisper, apply a little rosin to the base of the foot.
The design of the Chien is obviously vital and details of construction will be found on page 96 of the new edition Hurdy Gurdy Method . Many valid points affecting the tone and sensitivity are given there and I will endeavour to expand on some of them.
2 . The position of the notch should be the last adjustment . It is easier to make small adjustments with a half round needle file .
3. The lighter the chien is made, the more responsive it will be, up to the point where it becomes flexible and useless!. The size of the foot has a marked effect on the tone, generally, a smaller foot gives a brighter sound.
4.The chien foot can be positioned directly under the string and this will often work very well as it minimises the flexing mentioned above. The further away the foot is, the greater will be the volume as the foot is lifted further from the soundboard at each cycle. This can also have the effect of making the sound coarse.
5. The height of the chien should average 11 mm. Higher and the wheel - string distance is reduced and vice versa.
6. The tenon should not be a tight fit and efforts to achieve a perfect fit are largely unimportant as the sideways forces can make a perfectly fitted tenon rub against the mortice sides. A safer method is to taper the tenon in all directions so the only area of perfect fit is at the opening of the mortice.
7. The pivotal edge should be the only point of contact so it is advisable to cut a slight angle from the edge to clear the soundboard. Any lateral rocking is to be avoided, this can be ensured by imparting a very slight hollow to the edge so it tends to contact the soundboard at its ends.