wisdom of changing base tuning (or not)

[debra]

I have found them more often to go up, but that’s just based on empirical evidence with the few accordions I have tuned.

My experience is that only the reeds for high notes tend to go up (which is convenient as tuning them down a bit is easier than tuning them up).
With lower notes it's pretty much an equal mix of reeds having gone up or down. It's not just the reeds that go out of tune but leather valves may change over time as well and thus change the amount of resistance they offer to the airflow.

 

[pitzelberger]

Actually the standard in German accordion orchestras is 440Hz. Other types of orchestras may be playing at 442 or 443...
German accordion orchestras are dominated by Hohner accordions and almost all have a default tuning of 440Hz.

I was referring to the orchestras, where the two clarinetists are playing.

 

[debra]

I was referring to the orchestras, where the two clarinetists are playing.

OK. It is becoming a global trend for orchestras to ignore the ISO tuning standard (440Hz) and to play higher. 442Hz is used a lot.
It is a pity because one would hope that most people would follow an ISO standard (even though that is not mandatory), especially since there are instruments that are not easily changed to a different frequency. That's not just accordions, but for instance also pipe organs.
With NSAO (the Dutch Symphonic Accordion Orchestra) we have played together with organ on a number of occasions and are planning some more. Luckily most of us are tuned to 440Hz because that is what these concert and/or church organs are tuned to as well.

 

[Wheezer]

My experience is that only the reeds for high notes tend to go up (which is convenient as tuning them down a bit is easier than tuning them up).
With lower notes it's pretty much an equal mix of reeds having gone up or down. It's not just the reeds that go out of tune but leather valves may change over time as well and thus change the amount of resistance they offer to the airflow.

I am going to have all the leather valves replaced prior to tuning. Some of the notes, especially the low ones are gurgling at low volumes. Given the age of the instrument, I’m thinking that having all of the valves refreshed may be better in the long run than just replacing the ones that are currently problematic. “buy once, cry once”, as the saying goes.

 

[debra]

I am going to have all the leather valves replaced prior to tuning. Some of the notes, especially the low ones are gurgling at low volumes. Given the age of the instrument, I’m thinking that having all of the valves refreshed may be better in the long run than just replacing the ones that are currently problematic. “buy once, cry once”, as the saying goes.

That is a sound decision. The only downside is that replacing the valves, wax, then waiting to do tuning... means that this job is going to take about a month (not full-time work, but a lot of work and a lot of waiting).
Most often, when I get an accordion in for tuning and whatever else it needs, the owner wants it back within a week, perhaps two weeks tops. So there is never time to do a complete rewax and then revalve and then tuning job... (and they don't expect a huge bill either).

 

[Wheezer]

That is a sound decision. The only downside is that replacing the valves, wax, then waiting to do tuning... means that this job is going to take about a month (not full-time work, but a lot of work and a lot of waiting).
Most often, when I get an accordion in for tuning and whatever else it needs, the owner wants it back within a week, perhaps two weeks tops. So there is never time to do a complete rewax and then revalve and then tuning job... (and they don't expect a huge bill either).

I am thinking/hoping that in general, the wax is in pretty good shape,because the compression is excellent. But, I could be wrong. I have a paranoia about pulling bellows pins, so I won’t know for sure until I get it to the tuner for an evaluation.

 

[debra]

I am thinking/hoping that in general, the wax is in pretty good shape,because the compression is excellent. But, I could be wrong. I have a paranoia about pulling bellows pins, so I won’t know for sure until I get it to the tuner for an evaluation.

I was thinking about the rewaxing because replacing the valves on the inside of the reed blocks is a major pain without removing the reed plates...
It can be done, and I have on occasion done it for one or two notes but I cannot even think of the frustration ahead when doing a complete accordion like this.

 

[Big Squeezy Accordions]

My Stradavox was A443 when I got it. As it hadn't been tuned for many decades and was all over the place anyway, I rounded it down to 442. That's as far as I'd go, especially with nice handmade reeds like mine has.

 

[debra]

My Stradavox was A443 when I got it. As it hadn't been tuned for many decades and was all over the place anyway, I rounded it down to 442. That's as far as I'd go, especially with nice handmade reeds like mine has.

That is a sound decision. Going down by 1 Hz is certainly doable and probably not a lot more work than tuning to what it was supposed to have been when new. I have done this as well. But I have been tricked twice now by a request to go down by 1 Hz when it turned out the instrument was actually another 1 Hz too high. Going down by 2 Hz is not so good for the reeds and it is a lot of work. I generally refuse to tune down by 2 Hz but I have now learnt that I should only agree to go down by 1 Hz when the accordion on average is not more than 1 Hz too high. Having fallen into this trap twice now I most certainly will not do that again...

 

[Glug]

I am not a professional, but what I would do:

• Measure the frequency not only at a' but at multiple notes on multiple reed banks and on push and pull (ideally all notes on all read banks except the tremolo ones).
• Enter the values into an Excel sheet, which allows you to compute the cent deviation of the notes to the ideal frequency assuming a certain base frequency. Find the base frequency, which minimizes the average deviation over all notes.
• While doing so, control for air pressure using a manometer (e.g. see here how to can be done https://accordionrevival.com/ACCORDION_REPAIR_3.php)

There's also a free stats package that will fit an exponential curve to a set of data.
I've used it for many things, but here it's used to estimate mussette tuning: https://www.accordionists.info/threads/learning-to-tune.6469/#post-69758. Obviously you can also fit an exponential to straight tuning and estimate the 'best fit' A4 frequency.

"Something I found: free software to fit an exponential curve of the form a + b*exp(c*x)

basicTrendLine package: https://github.com/PhDMeiwp/basicTrendline
R Statistical Package: https://www.r-project.org/"

 

[pitzelberger]

"Something I found: free software to fit an exponential curve of the form a + b*exp(c*x)

Thanks, given that my real live profession is a Data Scientist, I am quite experienced with Python and have used the `scipy.optimize` package to fit tremolo curves of the form `beat in hz = a+b*c^x` with a,b,c being the coefficients to optimize for and x is a linear increasing number which doubles each octave

I am happy to share a ipython notebook if there is interest