How can G strings be considered comfortable

Simon Washer
Musician
Traditional European dance improvisation

m (Α): +43 [Ο] 68I.IΟ 3Ο 7Ο 9Ο
e: e-mail address

Hurdy gurdy FAQ - Frequently asked Questions



"What should a beginner consider when buying?"

Here is my personal opinion, as far as it can be conveyed in writing. The whole thing has become a little longer, because it cannot be answered in one sentence, which is why no one has apparently taken the trouble so far. In addition, this is of course a controversial topic. It is also about quality in instrument construction, about selling and therefore about money.
I have tried to put together my personal criteria that can be activated. Instruments that do not have to meet these criteria therefore do not have to be bad, can even be experienced individually as the ultimate best, but I would not recommend them as an instrument for learning.


So:

the instrument should
Have 1-2 melody strings
1-2 purr, or 1 purr with whole-tone changer
2 bordun strings
more strings are not to be mastered for the beginner, can at most be bought with for the future.

standard dimensions have:
length of the unabridged melody string (s) - 345 mm (+/- 5 mm)
crank length 65 - 70 mm

Have a standard keyboard with all chromatic half-tones and a tone range of 2 octaves, that is 14 keys in the diatonic row ('lower keys'; in traditional French 13 - without a seventh in the 2nd octave), and 10 keys for the chromatic ones semitone steps ('upper keys').
From the standpoint of playability, the diatonic and chromatic keys should be arranged in relation to one another in such a way that the division of the chromatic (upper) keys is in the middle of the diatonic (lower) keys only for the semitone steps in the diatonic (lower) keys row the division of the upper keys should be exactly above the division of the lower keys. Traditional keyboard layouts do not adhere to this requirement, which makes some sound connections more difficult to play on these instruments.
All of them, especially the high pitch of the keyboard, must work. Since you first have to learn to play this tone, it should be judged by an experienced hurdy-gurdy player. You can also have the seller play this tone for you. Statements such as 'these buttons are not used' should encourage skepticism.

Exactly question the statements of those willing to sell: even buying directly from the instrument maker is no security, because the philosophies and views on quality (keywords: 'cheap instruments', price war, 'authenticity') diverge very much in this area. Instruments are even more sold on because they are not good enough for the previous owner. So always ask about the motives for the sale and the pricing and listen carefully to the answer, and ask questions in a probing way. For example, what exactly is the difference to more expensive models from the same instrument maker.

When it comes to instruments for less than 1000 euros, my skepticism is very high; any restrictions must always be accepted. There are very recommendable but also very miserable instruments for around 1400-1600 euros, but also extremely bad instruments for 3000 euros on the market.

Hurdy-gurdy hurdy-gurdy should always be bought directly and not through intermediaries who usually have no information about the instrument at all. Always ask the seller about the included service and support.

Before buying, you should ask (and only buy if the answer is correct):

What is the wheel made of?
wrong answer: solid wood, solid wood, a board ...
correct answer: plywood, MDF, laminated wood, plastic, ...

How do you remove the bike?
wrong answer: is never necessary; you have to remove the cover, ...
correct answer: explain the method that can be carried out without special specialist knowledge.

The prospective buyer should sit down and let the seller strap on the instrument to secure the instrument. Remove the wheel cover as shown by the seller. Then take the strings off the wheel, how can the seller show, take the wheel in hand by the sides (do not touch the strings) and try to move it: can it jerk sideways, up and down, does that make a noise?
if ia, the warehouse is not in order.

Now take the axis where you left the instrument in your hand and try to jerk it. again that shouldn't be possible. Next, turn the crank without strings on the bike: there should be almost no noise, neither scraping / rustling nor rumbling or knocking.

Check whether the crank knob runs smoothly. There is a bearing in the knob, the knob must be able to turn easily and without resistance. If it wobbles or can be pushed back and forth, it causes noise. If there are no strings on the wheel, the resistance when cranking the wheel should only be very low, and the same when the wheel is in the down position. If turning is tighter at some points in the turn than at others, no thanks: that means repairs.

Carefully inspect the wheel surface. While you slowly turn the wheel watch for scratches, dents, notches and whether the surface is evenly shimmering smoothly in the light. The wheel surface should be in perfect condition when you buy it. It slowly gets worse from playing and has to be optimized by a specialist at longer intervals.
Claims made by the seller that 'has to settle in first' are false.

hold down a semitone key (upper row of keys) and open the tangent box: the key should not hinder opening. Not an absolute reason for rejection, but a construction flaw that is very annoying when fine-tuning the tangents.

For instruments with two or more melody strings, the tangents (frets) must touch the strings at the same time, i.e. with the same pressure on the key: lay the instrument flat, 'hang in' all melody strings and slowly press the key without cranking: Observe carefully whether the strings are touched at the same time, if not: with traditional wood tangents it means a great deal of time (unassuming in terms of handicrafts) to correct it, with adjustable metal tangents around an hour's work.

When inspecting the tangents, make sure that the strings have notched the tangents, this is a sign of prolonged use. New instruments don't have that yet. a simple test of the roundness of the wheel:

only 'hang in' one melody string (the seller shows how), so remove it with the wheel - all other strings are 'unhooked' (are not removed), while turning it with a tuner, observe whether the pitch changes noticeably, and whether this change in pitch depends on the position of the crank, i.e. whether the pitch fluctuates with the rotation of the wheel. If ia, the wheel is probably not round enough, so it must be straightened.

Let the seller tune the instrument:
observe whether the person has difficulties turning the pegs or letting go of the pegs (so that they do not maintain their position). If ia, no thanks. A good instrument in good condition should only be able to be tuned by hand without a tuning stick.
Turn the pegs yourself: is it reasonably easy, can the pegs be turned in any position or do they bounce out, do they jerk? Of course, you can't tune the instrument right straight away, but buyers can test the pegs to see if they are willing to buy.

Let something fool you:
Can be played both with and without a buzz, the instrument must always sound pleasant.
It is important to pay attention to whether the instrument is played with only one or with two melody strings: ask to play with both strings, then the layman can hear whether the instrument is well adjusted or not.

Basically, as a newcomer, you should rely on the expertise of a good, as professional as possible, hurdy-gurdy player. It probably saves a lot of money and with certainty of effort and disappointment to be advised by such a person, even if it may take a while before you can establish contact with a suitable person.
In any case, before buying, as part of the acquisition, it makes sense to take part in one or more courses with loan instrument (s) where a lot of experiences and contacts can be made (and different instruments can be tried out). After all, in the end one gives a sum that cannot simply be neglected by the vast majority.


I've had liquid rosin a few times belongs,
does anyone know a recipe and how to use it?

provisionally compiled after the mail exchange on the hurdygurdy mailing list about this topic, with contributions from Theo Bick, Neil Brook, Ben Grossman, Alden Hackmann, Colin Hill, S. Neumeier, Simon Wascher and others.



recipe

It is easy to make liquid rosin yourself. Simply dissolve crushed rosin in pure alcohol.
The solution shouldn't be too sticky: if you rub a few drops between your thumb and forefinger, there should be more friction but not really sticky to the touch. By adding alcohol or a thicker solution, adjust so that the optimum amount of colophony is applied to the wheel.
Basically this is the same solution that is used to insert a new wheel with rosin for the first time when building a hurdy-gurdy, but a bit weaker.

The most important factors for good liquid rosin are the quality of the rosin and the optimal ratio between alcohol and rosin. Both also depend on the playing style and the type of colophonium assignment.
A well-tuned instrument is also an important factor. If the pressure on the strings is too high or the padding is poor, even the best rosin will not help.

how do i use it

Unhook all strings from the wheel. Put a few drops of colophonium on a piece of cotton wool about the size of a pea and spread evenly over the entire surface of the wheel. Some people also use a brush or a piece of cloth for this.
Let the alcohol dry off briefly for a few seconds to a minute, turn the wheel and press firmly against the surface of the wheel with a wad of cotton wool. Through the development of heat, the surface is completely dried and smoothed. Finally, press the wad of cotton very firmly against the edges of the wheel to remove the colophony from there, this will improve the sound.
The application of rosin is correct if there is no scratching noise at a very low speed, then too much rosin has been applied, nor can the wheel slip under the strings: then the rosin application is too low. The prerequisite is of course that the pressure of the strings on the wheel is correctly adjusted.

Fine sandpaper (600 to 800) can help if too much rosin has been applied, but it is not necessary if the dosage is correct.

about the colophonium

At the beginning it is best to use a little of the colophonium block or powder that you have used up to now. A hurdy-gurdy is a bowed string instrument that uses the same type of strings as other bowed instruments. The colpophonium that you use for this should be one for violin viola or cello, you should keep your fingers off the exotic and experimental.

about alcohol

Pure 90-95 percent alcohol (ethanol) is recommended. Alcohol as it is used to disinfect the skin usually has only 70%, therefore dries more slowly and with its 30% water content may have a negative effect on the bike (with wooden bikes).
Spirit is the most common name for the 90-95 percent ethanol required for technical purposes, which is sold as a plaster or anti-freeze agent in drug stores, pharmacies, paint shops and petrol stations. It is coated with a particularly bad-tasting additive so that it is not drunk, and compared to the "wine spirit" intended for consumption, it is very inexpensive.
In the past, "spiritus" could also contain admixtures of methanol, but this is poisonous and is no longer contained in today's "spiritus".

to the bottle

For several reasons, it is best to use a bottle with a dropper insert, which is a plastic part that practically closes the bottle neck and only releases individual drops from the bottle. You can get it in any pharmacy, for example (you also get bottles with a pipette there, and even if the purchase order is correct, the sales staff will occasionally want to give you one by mistake).
There are several advantages compared to a bottle with a pipette: since the bottle itself contains the dosing device, one part has to be handled less. Even if the open bottle falls over, only a few drops are spilled.
In the case of bottles with a pipette, it happens again and again that they keep leaking, because the entire thread of the lid is on the one hand constantly stuck with resin and on the other hand is dissolved again when it is closed. In the case of bottles with a dropper insert, the colophony can only leak out in drops.

extras, advantages

A main advantage is that with every colophony application the wheel is thoroughly cleaned of grease and other dirt by the alcohol at the same time.

Normally, depending on the external conditions and the string pressure, the colophony application with liquid colophony lasts for about 2 to 20 hours, so it lasts longer than other methods of colophony.
Personally, I still have a block of colophonium with me when performing on stage because it is quicker to apply. That gives a certain security, but I hardly ever use it.

The wadding can be fixed on the string with the liquid colophony. On the one hand, the string can be made more adherent with a little bit of rosin on smooth, wound strings, on the other hand the padding of the string can be "glued" with a drop of rosin, for example to be able to turn in both directions without the padding solves.
If the padding does not come off the string easily, just loosen it with a few drops of liquid colophony.

is there ready-made liquid colophony to buy?

There is liquid colophony for violins to buy, but it must first be diluted to the correct strength with alcohol, there is a supplier in Germany for liquid hurdy-gurdy colophony: Natalia Issupow, and it can be obtained ready-made from hurdy-gurdy maker Wolfgang Weichselbaumer .


which moods and keys are possible with the hurdy-gurdy?

(currently in progress)
Basically there is no general norm for the mood of hurdy-gurdy gurgles, but there are a few moods that have gained importance through their distribution.
How you tune your personal instrument depends on a number of factors that will be explained here.
The first question is "who do I want to make music with?" It's frustrating to have tuned the instrument in G / C when the musicians you meet are all playing in B and Eb.
"Do I want to sing to the instrument?" If ia, the tuning of the instrument should be in the right key.
If there is no specific reason for a certain mood, there are a few arguments in favor of opting for a "usual" mood.

usual moods

G / C

In this tuning, the melody strings are tuned in G, with bordoons in G and C, the snarling string can be retuned to D. In this mood it is customary to play in G and C, including the minor and church tones on these basic tones (C and G Doric, Mixolydian etc).
Due to the existing snarling tones, it is possible to make music in the scales on the basic tones D and F without any great difficulty. Due to the open string G, A major is quite difficult in this tuning, and the appropriate bordoon tone is missing here.
By default, a six-string hurdy-gurdy in G / C has the following strings:
G ~ 98 Hz (G of the cello)
c ~ 131 Hz (c of the viola)
g ~ 196 Hz (g of the violin or viola)
snarling string:
c '/ d' ~ 262/294 Hz (d 'of the violin or viola)
melody strings:
g '+ g' ~ 392 + 392 Hz
if there are two melody strings, both are traditionally tuned equally in g '. If the resonance of the instrument supports it, it is possible and very beautiful to tune one of the two melody strings with a viola or violin G string an octave lower.
One advantage of the G / C tuning is that the keys are assigned the same way as with other keyboards: the diatonic key row corresponds to the keys of the C major. The accidentals (#, b) in the notation are therefore assigned to the upper keys of the keyboard, analogous to the piano.

D / G

This second standard mood comes from central France and is particularly suitable for dance music from this region.
The melody strings are tuned in D with bordoons and snarling strings also in D.
In this mood it is customary to play in D and G, including the minor and church tones on these basic tones (G and D Doric, Mixolydian etc).
It is recommended to tune one of the bordoons to G.
By default, a six-string hurdy-gurdy in D / G has the following strings:
D ~ 73 Hz (one tone above the C of the cellos)
d ~ 147 Hz (one tone above the C of the viola) or G ~ 98 Hz (G of the cello)
d ~ 147 Hz (one tone above the C of the viola)
snarling string:
d '~ 294 Hz (d' the violin or viola)
melody: -strings:
d '~ 294 Hz (d' the violin or viola)
d '' ~ 592 Hz (one tone below the e 'of the violin)
the two melody strings are traditionally tuned in octaves.

A.

This mood is common in Hungary. The melody string is tuned in E, the bordoon and the snarling string in A.
In this mood it is customary to play in A, including the minor and church tones on this basic tone (A Doric, Mixolydian etc).
Bordeaux:
A ~ 110 Hz
e ~ 165 Hz
snarling string
a ~ 220 Hz
melody string:
e '~ 330 Hz

Galician Zanfona, this instrument has no buzz. Here are the two standard moods:

DO

1. Bordon
c ~ 131 Hz (c of the viola)
2. Bordon
G ~ 98 Hz (G of the cello)
1st & 2nd cantantes (melody strings)
g '+ g' ~ 392 + 392 Hz
3rd cantante
g ~ 196 Hz (g of the violin or viola)

SOL

1. Bordon

2. Bordon

1st & 2nd cantantes (melody strings)

3rd cantante


There are a few additions to these standard tunings that can expand the tonal possibilities of the instrument.
That was already mentioned octaving the melody strings about g to g '. In the case of instruments with two melody strings, it is also possible to tune the strings to different basic tones.
quint-parallel
Obviously it is to tune the two strings in a quint distance either to be able to play pieces with the same set of fingers to a quint transposed or to play both strings together in quint parallels. For example, for the g 'melody string, a c' that can be played very well on its own or also a d '' that sounds very high on its own. A tuning with a g (viola / violin G) string and a parallel d '(viola / violin D) string is usually better here.
duodezim-paralelle
An interesting parallel tuning in which, for example, a g and a d '' string are played together or c and g '.


For intonation
(currently in progress)

the intonation of hurdy gurdy gales is not an easy thing. Due to the fact that a bordun tone also sounds together with the tones of the melody, all tones of the melody are related to this one bass tone. An equally tempered mood as it is common on modern keyboard instruments leads to unsightly interference tones (beats) with some tones.
It sounds much nicer when each individual note on the keyboard is tuned to the bordun. The resulting intonation is called pure intonation because it aims to minimize the rough and unclean-looking beats.

In practice, this is done according to Gehoer, a method will be described here, but of course there is also a corresponding theoretical explanation:
A sound wave consists of regular compressions and dilutions of air. When two sound waves meet, they overlap and are, so to speak, added together. The thickenings and thinning meet regularly.
If these sound waves are in a simple numerical relationship to one another, the waves that arise in this way are also simple and regular, the tones merge into one another.
If the waves are similar, but not in a simple, integer relationship to one another, pulsating, restless interferences arise that are exhausting to listen to, one could also say that they are perceived as wrong.
Expressed in numbers:
Every sound source consists of a bundle of sound waves, the partial or partial tones. The following series of numbers assigns a digit to the partial tone of a sound source, 1 corresponds to the fundamental tone. Each of these digits (or their doubling) also corresponds to the frequency of the partial tone. So you can also arrange the corresponding tone names:

12345678910111213141516
C.C.GC.E.G C.D.E.& nbspG  HC.

as you can see, not all seven tones of the diatonic scale are included in this series. You could, for example, use the seventh and eleventh partial tones, and do so, for example with simple natural trumpets, but for reasons that are related to the fact that the numerical relationships remain as simple as possible (to beat beats, especially in connection with harmonies avoid) European music mostly uses a diatonic scale that overlays two such partial tone rows and thus only uses the partial tones 2, 3 and 5 (the first three prime numbers) and their multiples the other partial tones (7, 11,13) substituted.
Probably the simplest series of numbers that represent all tones of the diatonic series:

2427303236404548
GA.HC.D.E.F #G
8910       1516       8910       89       1516


if you look at this, you can see that the whole scale is made up of three different intervals:
8: 9, 9:10 and 15:16 One could also say that out of large whole tones (8: 9), small whole tones (9:10) and even smaller intervals (15:16), let's call them half -toene, which, of course, strictly speaking, they are not. The structure of a diatonic scale can therefore be represented as follows:

C. gr D. kl E. H F. gr G kl A. gr H H C.

This structure is always the same and relates to the basic tone of the tone type (the tonic). So if you change the key, this sequence begins with the new basic key:

G gr A. kl H H C. gr D. kl E. gr F sharp H G

It is very important for the hurdy-gurdy tuning to understand what this means when you want to play the two types of notes C and G on the instrument:
The following table shows both types of tones in which we usually play on a hurdy-gurdy in G / C next to each other:

      C.grD.klE.HF.grG

kl

A.grHHC.
GgrA.klHHC.grD.klE.grF #HGgrA.klHHC.

You can see that the interval sequences largely agree (the F sharp generally has its own key), but not at one point: in C major there is a small whole tone, in G major a large whole tone (the H is not affected because the interval to G remains the same: a small plus a large whole tone).
This means that the pure A in C major is significantly lower than in G major. Since both tones are of course played with one and the same key, you have to find a solution to this problem when tuning.
Since you can increase the tone a little if you press the key harder, a compromise is usually tuned, the tangent turned into a middle position a little too low for G and too high for C. So you can use the A in G major intone upwards and there is as little wrong as possible in C.
With each additional key used, there is also another tone that has to be tuned as a compromise (with quint-related tone types always the tone that is the sixth in one key and the second in the other).

On the occasion of a discussion on another mailing list, I dug up a little text of mine for intonation:

pure intonation in C and G and the pitch A

The problem is that in the pure intonation, of all things, the A changes its pitch when changing between G and C. If this tone is now accepted as a fixed standard tuning tone, practically the entire remaining scale is shifted in different directions: in G down in C up.
As a result, very large discrepancies can sometimes occur here, sometimes in the range of ~ ten Hertz in the octave when two instruments are tuned in on different types of notes. So it is not enough to simply refer to the standard A, the key must also be fixed.

C tuned to standard AG 'derived from C
G'396 Hz (C / 4x3)396 Hz (C / 4x3)
a '440 Hz (standard A)* 445.5 * Hz (G '/ 8x9)
H'495 Hz (C / 16x15)495 Hz (G '/ 4x5)
c ''528 Hz (A / 5x3)528 Hz (A / 5x3)
d ''594 Hz (C / 8x9)594 Hz (G '/ 2x3)
e ''660 Hz (C / 4x5)660 Hz (G '/ 3x5)
f ''704 HZ (C / 3x4)f # '' = 742.5 Hz (G '/ 8x15)
G tuned to standard AC 'derived from G
G'391.11 Hz (A / 9x8)391.11 Hz (A / 9x8)
a '440 Hz (standard A)* 434.57 * Hz (C '/ 6x5)
H'488.88 Hz (G / 4x5)488.88 Hz (C '/ 16x15)
c ''521.48 Hz (G / 3x4)521.48 Hz (G / 4x3)
d ''586.67 Hz (G / 2x3)586.67 Hz (C '/ 8x9)
e ''651.85 Hz (G / 3x5)651.85 Hz (C '/ 4x5)
f # ''733.33 Hz (G / 8x15) f '' = 695.32 Hz (C '/ 3x4)


if you use a tempered G as the standard tuning tone, as happens when the accordion specifies a G,

volume(numeric)(in Hertz)
A.1.12246440 Hz
G = 1.00000 = 391,996 Hz


then the session as a whole has probably decided on the 2nd variant (G tuned to A, C tuned to G) which means an improvement, but the difference in voice between the tempered a 'and the so tuned a' of C is at least 6.43 Hz!

It would be better if the tuning tone A was seen as being in the middle between G and B:

G: H = 1: 1.25
G: A = A: H
1.0000: x = x: 1.25
A = 1.11803
G = 393.549 Hz

This means that the deviations between the equally floating moods and the pure moods for C and G are evenly distributed and kept as small as possible. The difference between the two a 'remains, of course, but becomes a little smaller (5.46 Hz), and the difference in voice to the equal tuning is also minimized. Here is a table that compares an equal tempered tuning, such as the accordion (a '= 440 Hz), with the pure tuning for G and C, based on the assumption that the pure tuning G' is tuned to 393.549 Hz will (rounded values).


volumelevitatingGC.
G' = 392.00 Hz393.55 Hz (+1.55)393.55 Hz (+1.55)
a ' = 440 Hz442.74 Hz (+2.74)437.28 Hz (-2.72)
H' = 493.88 Hz491.94 Hz (-1.92)491.94 Hz (-1.92)
c ' = 523.25 Hz524.73 Hz (+1.48)524.73 Hz (+1.48)
d ' = 587.33 Hz590.32 Hz (+2.99)590.32 Hz (+2.99)
e ' = 659.26 Hz655.92 Hz (-3.34)655.92 Hz (-3.34)
f ' = 698.46 Hz-699.64 Hz (+1.18)
f # ' = 739.99 Hz739.90 Hz (-0.09)-


That may also explain why G bagbags are often perceived as being in high pitch: on instruments like the violin, the A is the fixed reference point, the G is tuned to 391.11 Hz is significantly lower than the G of the G / C bordun instruments with 393.55 Hz with which, however, only a pure tuning that is as little rubbing as possible with the standard A is aimed for.


fine-tuning the tangents


why does the snar not work so properly?

provisionally compiled after a mail from me on the hurdy-gurdy mailing list about this topic



One simple answer
first a few practical tips:

The function of a good purr is very dependent on the rosin and the padding.
The padding is probably to blame for everything.
use as little cotton as possible, almost none. In any case, the wadding must not form a significant thickening of the string, but rather a regular 'film' around the string.
A detailed description with pictures is available from Helmut Gotschy's 'padding assistants':
http://www.gotschy.com/deutsch/service.html
A worsening response of the purr is an indication that rosin should be applied.

Use 600 grit sandpaper to regularly remove all rosin from the wheel * edges * it makes scratchy noises there.

Carefully clean the tilting edge and the abutment of the Schnarr web, there sometimes dust and rosin collects and disrupts the tilting movement.

At least important when making a buzz: work the tilting edge, the striking surface and the string notch very precisely when making a buzz.
The pressure on the strings should only be assessed (and the notch possibly changed) if the cotton and colphonium are optimally adjusted.

more precise details the function of the buzz is the result of around a hundred variable factors, the effects of which depend on one another. A single change may therefore have opposite effects in conjunction with the other factors. a simple piece of advice 'do this or that' can therefore usually only cause the advisor to be considered incapable (at the bottom you will find an attempt to answer).

so that you have something to try, here is a list of factors that in any case or under certain circumstances cause something or the opposite:
Wheel surface:
condition, regularity, width of the support, condition of the wheel edges, addhaesion, quantity, type, distribution of the rosin
wadding
material (cotton, silk, viscose) width (position) thickness and regularity of the padding, density, i.e. degree of matting and hold on the string, wear and tear, soiling, (I use cotton capsules from the florist)

String pressure, one of the more important easily changeable factors (minimal changes have maximum effect), closely related to padding and colophony.

The string:
String thickness, material and quality: ie tension, flexibility, density, weight, (I use KF strings [a carbon plastic] sold for harp or guitar) Condition of the string: irregularity, damage

Course of the string:
vertical deflection: angle from the saddle to the bridge and from the bridge to the edge of the ceiling, horizontal deflection: deflection angle from the saddle to the wheel, from the wheel to the bridge, deflection by the auxiliary string or the wedge. Distance between the auxiliary string and the bridge, proportion of the string parts to one another: saddle - wheel | wheel - bridge | bridge - auxiliary string knot (wedge) | auxiliary string knot (wedge) - ceiling edge.

Auxiliary string:
Distance of the auxiliary string knot from the snarling bridge, vertical attachment angle of the auxiliary string, knot and material of the auxiliary string.

condition of the saddle notch, the bar notch.

Schnarrsteg:
shape: height, length, width, shape, proportion, weight distribution, surface
Status:
the striking area, string notch and the tilting edge.
material:
density, weight, hardness, homogeneity, flexibility (maple remnants from instrument construction are very good)

state of the counterpart,
condition and material of the impact area (addhaesion, density, hardness, flexibility ...)

the function of a purr is also influenced by the vibrations of the other strings, and especially other purrs on the instrument.

Then there are factors that influence the snarling technique and thus the player's ability to snarle:
rotational resistance, and regularity of the run in the axle and knob bearings, crank length, knob shape, surface and material, directness of power transmission (flexibility of the crank).

and, last but not least, individual technology and skills. A beginner has different demands on a buzz than a professional.