Yamaha CP-70 & CP-80 voicing, etc.

Billbrpt@AOL.COM Billbrpt@AOL.COM
Sun, 1 Nov 1998 18:46:42 EST


Dear List,

I have discarded all recent posts and have unsubscribed for a few days but
this is one from several days back that I wanted to answer so I hope that no
one else covered the subject.

The usual voicing requirements and techniques for acoustic pianos do not apply
the Yamaha "electric" grand.  The hammers are covered with buckskin so they
last a lot longer than felt and do not present the same problems.

There is no need to harden or soften the buckskin material.  Since the piano
is only used with an amplifier, the desired tone can be manipulated with the
piano's and/or amplifier's tone controls.

When the hammers' buckskin becomes worn through, you must replace it.
However, there is a good stopgap measure you can use to get as much as three
times the wear out of them.  Since the action has no una corda (soft) pedal
and the action does not shift, you can alternately space all the hammers to
the right, then to the left to use the unworn portion of the buckskin.

TUNING STABILITY.  It is true that because the piano has no soundboard, once
it is in tune and the normal stretching period of the strings is over, it can
be a remarkably stable instrument.  However during the initial tunings and
pitch raises, it will be very unstable because there is no bridge with pins
that create a "dog leg" deflection of the strings.  There is only a smooth,
magnetic pick up and a hitch pin.  Therefore, if you change the pitch of one
string radically, say a half step, it will easily affect the other side of the
unison.  You will have to do repeated tunings to stabilize the piano to a
point to where it is good enough for a performer.

TUNING DIFICULTY IN THE BASS.  The strings are very short and fat compared to
any acoustic piano.  The scale is more compromised than any spinet.  You can
expect "growly", difficult to distinguish bass notes, especially the lowest
ones.  On the 88 note model (CP-80), the lowest strings, A0 to C1 will be a
real challenge. 

 If you are an aural tuner, you'll just have to try finding the best sound by
alternately pulling the string sharp then flat and find the point which sounds
best.  If the string is very far off pitch, you might not know whether it is
already way too sharp or flat.  You can use one of the techniques that are
used on some consoles or spinets which have essentially the same problem.  The
strings are so loaded with inharmonicity, that you can't be sure of what the
pitch is supposed to be.  Play a descending scale or arpeggio ending with the
note to be tuned.  This will tell you whether the note is flat or sharp.

Ironically, the very fine Bosendorfer Grands that have a whole sub octave from
C0 to B0 can present the same problem to some aural tuners.  I had heard back
in the 80's that there were a disproportionately high number of orders for the
C0 strings because apparently, many were broken when a tuner could not
distinguish the proper pitch.

If you have a Sanderson Accutuner (SAT), I have an 88 note program for the
CP-80 (it is compatible with the CP-70  too) of the usual Equal-Beating
Victorian Temperament I tune.  It was done for a performing artist who still
uses the instrument professionally.  

While he plays Country music, the temperament is compatible with all
contemporary styles:  jazz, Rock, Country, New Age, etc., as well as all
classical styles.  There may be others on the List who have a perfected ET
tuning or the chart that Yamaha published.  If anyone would like this tuning,
I will be glad to post it but it means a lot of work for me since I have no
good way of transferring the information to the computer other than by a
manual transcription which is subject to error.  Getting it into a computer
file accurately takes time so I would like to be sure that my efforts are
going towards someone who really wants and needs the information.

Schaff Piano Supply has the specifications for the wound strings.  You can
order them by the set or individually by the number.  If it is a heavily used
piano, it is a good idea to have a whole set always on hand and replace any
used strings form it as they are installed, thus keeping the set complete at
all times.  Remember that the winding put on strings made in America is
clockwise.  The Japanese made strings are wound counterclockwise.

The action is well made and needs very liitle regulating.  Keeping the flanges
tight and a good hammer line are the most frequent requirements as they are
with most any grand action.

I used to tune a lot of these in the early to mid 1980's.  They have largely
been replaced by Electronic Keyboards of one sort or another by hard working,
traveling musicians.  They are nevertheless, unique as the Fender Rhodes piano
was and some musicians still prefer them.

Sincerely,
Bill Bremmer RPT
Madison, Wisconsin



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