Tension Difference between 435cps and 440cps

[Farrell]

> As I have done a lot of this sort
> of things over the past 28 years, I will be happy to counsel anyone who is
> interested.

Hi Joe, I am very interested in learning more.

> these instruments should NEVER be used for students

Why?

> If you are "restringing" one of these
> instruments, you should ALWAYS evaluate the scale using 435cps, (or other
> standard, such as 425cps for instruments that are pre-1870's), then reset
> the pitch standard to 440cps and "rescale" appropriately, keeping all
> tensions within the "original scale" plan.

Are you saying to rescale with A440 in mind, but keeping all tensions close
to that of the original design? That would mean using slightly thinner wire
for each respective note?

Terry Farrell

----- Original Message -----
From: "Joseph Garrett" <joegarrett@earthlink.net>
To: <pianotech@ptg.org>
Sent: Tuesday, September 18, 2001 1:14 PM
Subject: Tension Difference between 435cps and 440cps


> List,
> Years ago, I calculated the difference between 435cps and 440cps. The
> average difference was approx. 5 lbs per string. I'll let you do the math.
> Most "plates" are way over-engineered. However, there are those who
designed
> within a "gnat's eyebrow", so caution is always advisable. Hope this
helps.
> While we're on the subject of pitch, I personally have not been able to
> ascertain WHEN "International Pitch" was established or even who did
> establish it. There doesn't seem to be any documentation regarding this
> pitch establishment. If any one out there knows, please post it for all to
> see.
> Regarding Square Grand tuning pitches, etc., if you are tuning one with
the
> original strings, it is best to use 435cps as a standard. As these
> instruments should NEVER be used for students, the pitch difference is of
no
> consequence. I should say that all instruments of this kind should be
tuned
> to their "designed pitch", as they will be more stable and the chance of
> structural damage is lessened. If you are "restringing" one of these
> instruments, you should ALWAYS evaluate the scale using 435cps, (or other
> standard, such as 425cps for instruments that are pre-1870's), then reset
> the pitch standard to 440cps and "rescale" appropriately, keeping all
> tensions within the "original scale" plan. As I have done a lot of this
sort
> of things over the past 28 years, I will be happy to counsel anyone who is
> interested. Also, I do "Scaling" service.
> regards,
> Joe Garrett, Oregon
>