Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum CHAS PREPARATORY TUNING

Hi Jake.

..."No, no. The problem is, if memory serves me correctly, later in the sequence, you refer to a narrow octave as a flat octave. As a result, I assumed that the sequence was saying that the A3-A4 octave should be narrow. (Although I doubted that you meant to say this.)"...

Would you be able to point out where - later in the sequence - I refer to a narrow octave as a flat octave?

..."A note for novice tuners explaining how an octave can be made narrow or wide might be good,..."...

Do you mean this(?): ...we can make a "wide" interval either by sharpening the top note or by flattening the bottom note; and we can make a "narrow" interval either by flattening the top note or by sharpening the bottom note.

Someone says that ET octaves can be narrow, I cannot (and would never) say that. Chas ET octaves are wide and get slowly wider and wider.

..."but my problem was just with the use of the word "flat" speaking of an octave. I would suggest using simple, declarative statements such as: "Tune A3 very slightly flat from A4, just at the edge of beating, creating a wide octave." (In other words, write full sentences, so that a simple verb such as "tune" or "raise" or "lower" applies to one of the strings in the interval in each step.)"...

I agree, your way is much clearer. Thank you.

a.c.

CHAS THEORY - RESEARCH REPORT BY G.R.I.M. - Department of Mathematics, University of Palermo - 2009, Italy:
http://math.unipa.it/~grim/Quaderno19_Capurso_09_engl.pdf

Article by Professor Nicola Chiriano - published by P.RI.ST.EM (Progetto Ricerche Storiche E Metodologiche) - University "Bocconi" - Milano, 2010 - (Italian):
http://matematica.unibocconi.it/articoli/relazioni-armoniche-un-pianoforte

Chas Recordings:
http://www.chas.it/index.php?option=com_content&view=article&id=64&Itemid=44&lang=it

I cannot find the sequence on your site, now. I apologize if I misspoke, but I thought that the near the end, a narrow octave was defined as flat.

In any case, I'm looking forward to your revisions, to hearing the results as we attempt the tuning, and reading the ongoing discussion. I hope that your holidays were good, and that many songs were played on pianos that you tuned.

Happy New Year.

Hi Jake,

Thank you for your words. I've checked the website, you'll find Chas sequence here:

http://www.chas.it/index.php?option=com_content&view=article&id=40&Itemid=38&lang=en

From another thread:

Re: tuning the easy way? #1824040 - Yesterday at 12:00 PM

partistic:

..."...you would have to pay attention to the tuning pin movement, if you would like to have a decently stable tuning. It is important not to have a clockwise twist on the tuning pin, since hitting the strings with the hammers adds counterclockwise torque making the twist likely to untwist and detune the note."...

In my opinion you (partistic) managed to word that fundamental issue very nicely. I hope to be able to deepen on that (with you All), as in my experience pins control and "stable tuning" enable us to move towards our favorite tuning form.

Personally, I "charge" all pins also with a "counterclockwise torque". In fact, the "counterclockwise torque" is what is meant to have to determine the actual frequency. In other words (perhaps you can help me), the correct frequency must be the "natural" outcome, resulting from the balance between the string's pulling and the pin's counterclockwise "charge".

What about you?

Regards, a.c.
.

Hi Alfredo,
I just wanted some clarification. When speaking of "counterclockwise torque", does that mean that you tune the note as normal and then, at the last minute, twist the tuning lever counterclockwise just a little bit, and then leave the note like that? Does this make it more stable in your experience? In other words, when and how much counterclockwise torque do you apply?

Thanks!
-Erich

Hi Erich,

Let's consider the case of a "normal" pin and say that I'm tuning a flat note: while I turn the hammer clockwise, I evaluate how much clockwise torque and pin bending is taking place for the pin to turn at its bottom (down inside the pin-block). This allows me to get an idea of the pin's behavior and lets me guess the over pull. In the meantime I'm getting passed the "right spot"; then I can over pull, knowing that in order to get back to the right spot with the correct "pin charge" I'll have to "subtract" the clockwise torque and pin's bending (on a grand), possibly gaining the right spot with a (very) small amount of counterclockwise torque and (very) little pin-bending towards the speaking length of the string.

You ask: how much counterclockwise torque do you apply?

There I evaluate the pin's propensity to move; in other words, how much force (on the pin) would make the pitch flat or sharp: I refer flat Vs sharp propensity to the pin's counterclockwise torque and bending, and measure the pin's propensity (to flatten or sharpen the pitch) by touching lightly the tuning hammer. The flat Vs sharp force rapport I "normally" establish goes from 7/3 to 8/2, meaning that I need 7 or 8 points of push-flat force against 3 or 2 points of pull-sharp force.

I hope I could answer your question, perhaps you can word this practice more clearly. Please let me know if this post is only more confusing and I will delete it.

Regards, a.c.

Alfredo,

In the tuning sequence, you DO refer to a narrow interval as flat. Here's the line, from near the end:

"So far, apart from A3-D4, I have stretched “flat” (narrow) –
now I’ll stretch “sharp” (wide)…"


When are you going to do that video of you tuning?

Thanks Alfredo. Most of it makes sense. I think that I naturally or intuitively do this already to some extent (maybe not as accurate or calculated as you though). I pull slightly past the correct pitch, and then ever so slightly turn (or just touch)the tuning lever counterclockwise. I think this more or less along the lines of what you are doing, right?

One thing I couldn't figure out from your post though was the term 'Vs'. What is a 'V'?

Thanks again!
-Erich

"versus"

Ah - thanks!

Hi ChickGrand, thanks for helping, and thanks Jake.

Hi Erich, You say ..."I pull slightly past the correct pitch, and then ever so slightly turn (or just touch)the tuning lever counterclockwise. I think this more or less along the lines of what you are doing, right?"...

In general I think that's correct, I understand that from a higher pitch you get down to the right spot. But that, to me, means that you take away some clockwise torque only.

These are (more or less) the steps I refer to (in general):

1 - Turn the lever clockwise (apply and evaluate pin torque and bending)
2 - Turn clockwise (you must feel the pin rotating at its bottom)
3 - Turn clockwise (overpull - the above and this, all in one go - how sharp? It depends on the pin torque-bending/rotation rapport)
4 - Turn counterclockwise (for zeroing clockwise torque while you are still high in pitch - the pin must not rotate)
5 - Turn counterclockwise (get passed the right spot - now going flat you "charge" the pin - the pin has not rotated)
6 - Release the lever and help the pin's setting (now your pin has a residual counterclockwise torque that can balance the string's tension and the hammer impacts)
7 - Check the pin's charge (as explained in a previous post)

Of course, avoid practicing on a piano that you want to preserve.

To go through steps 1-2-3 will take one or two seconds; steps 4 and 5 may require more time/seconds, depending on the pin. Few more seconds for steps 6 and 7.

All this to say that many beginners are very concerned about the pitch, and many of them go for the pitch on its own, mainly concentrating on that. But really, in order to hear pitches and beats, after a while, you do not need to concentrate, actually you'll hear all that even if you do not want to. What I concentrate on is the pin's behavior, the amount of torque it can take and how it turns inside the pinblock.

Regards, a.c.

Edit: This post is about the "pin charge" issue; do not forget to distribute the string's tension on its three lengths.

Thanks for the detailed explanation Alfredo. I understand now what you are trying to accomplish. I must say that I have not tried this "charging" technique before. It is very interesting and I might give it a try on an older piano that I have access to. Always something to learn!

#1909239 - June 06, 2012 12:10 PM Circular Harmonic System (C.HA.S) Tuning

Weiyan Offline
Full Member

Registered: October 05, 2011
Posts: 362
Loc: Hong Kong

I am practicing CHAS tuning with the help of Issac.

I am using Afredo Capurso's Procedur.

This is my exercise today.

http://soundcloud.com/weiyan-1/thirds-6-june-2012
M3 progression

http://soundcloud.com/weiyan-1/fourths-6-june-2012
Fourths progression

http://soundcloud.com/weiyan-1/fifths-6-june-2012
Fifths progression

C-G / D-G, either one of these intervals too fast.

Suggestions are welcome.

Thanks you.

- . - . - . -

Hi Weiyan,

Few words in general:

1 - remember that any pitch can move a little bit at any time;
2 - after you expand your octave, you will be able to countercheck all notes from A3 to A4 and correct them even more;
3 - always relate (in your mind) one interval to another one, make a relation between intervals, never think that you are tuning one single interval;
4 - at this stage, do not look for perfection.

First consider (and tune) four notes, A4, A3, D and E (or E and D); you will need to evaluate these 4 notes (five intervals) together, evaluate their relation, because the octave, two 4ths and two 5ths will allow you to set the premises.

Leave A4 a little bit sharp (high in pitch), A3-A4 must be very very little wide, you would say it is just, beat-less, but you must be able to notice that it has some life. Play your octave and, before the sound goes off, you must be able to notice that it is going to "open", it want to grow in a sort of m…muuuuuoooooaaaa, it is not still/dead.

Tune D4 to A3 - That is a 4th, so sharpen D from just, find 1 bps (not more) and make it, if you can, just a little bit slower or leave it like that. In your rec, it is too just.

Check D4-A4, this 5th must sound almost just, very little life in it. In your rec., it is too narrow.

Tune E4 to A3 - That's a 5th, so make it narrow by lowering E4 from just. In your rec. it was quite good.

Check E4-A4, this 4th must be wide, around 2 bps. In your rec. it was too just, you needed A4 a bit higher.

So you have:

A3-D4 (4th) almost 1 bps (in your rec. it was too just)
D4-A4 (5th) almost just (in your rec. it was too narrow)
A3-E4 (5th) with a very slow beat (in your rec. (say for now) it was good
E4-A4 (4th) faster than A3-D4, almost 2 bps (in your rec. it was too just)

In bps order (from faster to slower):

E4-A4 (4th) faster than A3-D4, almost 2 bps (in your rec. it was too just)
A3-D4 (4th) almost 1 bps (in your rec. it was too just)
A3-E4 (5th) with a very slow beat (in your rec. (say for now) it was good)
D4-A4 (5th) almost just (in your rec. it was too narrow)
A3-A4 (in your rec. it was too just)

Please tell me if my English allows you to follow. If you like, make a rec. with only these five intervals. Same recording speed and method.

Regards, a.c.
.

Hello ALfredo, you say :



My experience (indeed once the technique is more or less mastered) is that at the contrary, a pianao that tend to show apoor holding and a too smooth pin rotation, will have its grip raised and way more than I was expecting.

I finally wondered if the pin does not get "twisted" some, so its grip get better.
I also noticed that on a really poor piano where the pin slips again and again, making the whole process (un charging, raising very slowly overpulling and torquing back) raise the grip after 3 or 4 times it is done.

There I wondered if when we uncharge then turn (very slowly) we are not reorienting a little the fiber inside the hole, that in the end provides a little more grip.

Naturally I would have think that the more I manipulate the pin in an old tired block, the more it get tired and slippery, but my experience was exactly the opposite.

SO working on any piano to learn the method can be done in my opinion , but care may be taken to respect well the orientation of the tuning lever so to avoid undue stress on the "bed" of the pin (the +-45°-60° part of the hole where the pin is really braked).

Best regards...

Afredo:

Thank you. I can here the beats in the record. Its easier to here beats in record.

For F-A, I feel its too quiet, now confirmed my hearing. Thank you.

Your English is easy to understand, except the word "just". Sometimes its may interpret as correct in ET, sometimes it may be refer to pure interval. If the just is refer to ET, not help to me. I am not trained to tune ET aurally, although had practice ET 4th/5th for a month.

Going to today's practice session.

Thank you..

This is today's practice.

Tried to correct last tuning, but one note slipped away. So retune from ground.

http://soundcloud.com/weiyan-1/chas-octave-8-june-2012
http://soundcloud.com/weiyan-1/thirds-8-june-2012
http://soundcloud.com/weiyan-1/fourths-8-june-2012
http://soundcloud.com/weiyan-1/fifths-8-june-2012

The frequency of this octave:

A3: 220.1
A#3: 232
B3: 246.7
C4: 256.9
C#4: 276
D4: 294.3
D#4: 308.8
E4: 329.6
F4: 347.3
F#4: 369.7
G4: 390.6
G#4: 413.8
A4: 441.1(Attack is 442)

Self critique:

Thirds:
A#-D: slow
D-F#: slow
D#-G: fast
F-A: slow

Fourths:
A#-D#: fast
C-F: Fast
E-F: Slower than previous intervals

Fifths:
B-F#: Fast
C-G: Fast
C#-G#: Fast

May be G-E too slow???

thank you for suggestion.

Good job, Weiyan.

Honk Kong time is 9.21 pm, I am writing now so that you can read this.

I have played your recs only once, to get an idea. Let's see your first rec (octave).

These are your "base" intervals (Please notice, the second last is not A4-E4 but A3-E4):

A3-A4 - A bit too wide. Listen how you can hear some movement very soon, at the beginning, too soon, you want that to happen a little bit later.
A3-D4 - Too wide. Can you hear 2+ bps?
D4-A4 - Nice. More typical for A3-E4. Make it less narrow.
A3-E4 - Nice.
E4-A4 - Too wide. Can you hear 3+ bps?

Now you can see (next it will be "visualize" in your mind) that:

A4 is too wide for A3 and E4
D4 is too wide for A3
D4-A4 is very close

What can you do?

You put a little bit down (lower in pitch - perhaps with a forte blow) A4 and D4. Also, you want D4 and A4 less narrow, so D4 must go down (in pitch) a bit more than A4.

I will analyze attentively your other recs tomorrow, please tell me if you can follow.

"Just" is referred to beat-less, still, no-beating intervals.

Regards, a.c.
.

Hi Afredo,

Refresh the browser before switching off the computer, I saw your reply. Thank you.

For counting beats, I have to take more exercise to learn counting beat. I think in CHAS is easier to count beats.

A3-D4: 1bps
E4-A4: 2bps
D4-A4: nearly no beat. In the procedure sheet, its "faint beating". I guess its nearly just.

A3-E4: 1.5 beats / 3s. This is most difficult interval. So I focus on other interval. If the other three interval beats correct, this will be correct.

Counting 1 or 2 bpse is easy to count 3.5 beats in 5 second.

For hearing the beats, its easier with recorded sound. In real tuning session, if stand up in tuning position, the beats are not so clear. When seating down, the beats are clear.

The width of A3-A4 is difficult.

Its good idea to focus on the first octave and the four intervals. Will going on practice tomorrow. Hopefully I had a correct pitch piano to play on Sunday.

Best wishes to all friends here.

Weiyan

Hi Alfredo, Weiyan~
Just tuned in to the discussion. I love this stuff!!!

Here's my suggestion. Hope it helps...

As for making A3-A4 slightly wide, compare the beat rate from F2 to each, making A3 beat ever so slightly slower than A4, taking into account you've already set A4 at 440. In a perfect world A3 beats half as fast as A4, so it needs to beat ever so slightly less than half.

Glen

Alfredo, here is a short sample tune I recorded right after a tuning in April. I hope you are doing quite well!
https://www.box.com/s/778175e3b3395ffd8264

Say something nice Alfredo after one year of tuning I find Glen is at a very good level and find a personal tone. I agree 100% with his unisons and I like the global color.

How did you make that temperament , Glen ?