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WARM STOP
The Sanderson Accu-Tuner IV has a time out circuit that is set to half an hour. To turn off the
Accu-Tuner for a phone call without losing the settings, use the warm stop procedure. The Accu-
Tuner will re-start with the same settings still turned activated, such as: auto-stepping,
temperament, sequencing or double octave beat and the Page, Octave and Note. If the On/Off
button is used to turn off the Accu-Tuner, the Accu-Tuner will turn on in the calibrate mode and
when the TUNE button is pressed none of the previous settings will be preserved.
To use the warm stop feature follow the procedure below:
1)
Hold down the SHIFT 2 button
2)
Press the DISPLAY button
To turn the Accu-Tuner back on press the ON/OFF button the same as if the Accu-Tuner had timed
out.
ADJUSTING THE DOUBLE OCTAVE BEAT
First let’s explain the basic outline of the Double Octave Beat (DOB). The DOB feature allows the
technician to adjust the width of octaves without altering the FAC measurements. This will allow
the tuning to be tailored beyond the FAC calculation to suit the preferred style of tuning or to
better fit to the scaling of the piano. It is possible to adjust the D.O. Beat either before or during
the tuning.
The Accu-Tuner IV when it is first turned on calculates one-quarter to one-half beat per second for
all double octaves, as a standard FAC calculation. The D.O. Beat control allows the technician to
add/subtract stretch to the tuning that the Accu-Tuner calculates. If the tuning sounds contracted
in the temperament, hold down the shift and press the D.O.Beat button up. If the tuning sounds
too wide in the temperament, hold down the shift and press the D.O.Beat button down. The D.O.
Beat setting will start at 0.0 and adjust up/down by tenths of a beat. The higher (positive) the
D.O.Beat number is; the wider the stretch will be for each octave. The lower (negative) the
D.O.Beat number is; the narrower the stretch will be for each octave.
Double Octave Test
Increase in Beats per second
A0 to A2
0.1
A1 to A3
0.2
A2 t o A4
0.4
A3 to A5
0.8
A4 to A6
1.6
A5 to A7
3.2
If the D.O. Beat were increased by 0.4 the A2 to A4 octave would be increased by +0.4 beats per
second over the standard FAC stretch tuning. The amount that the D.O. Beat affects the tuning
will increase as the octaves increase. The table above outlines the effect of increasing the D.O.
Beat by 0.4.
If the FAC tuning isn’t creating the preferred tuning and would like narrower or wider octaves,
then adjust the DOB before the Accu-Tuner calculates the tuning. If the FAC style of tuning
normally is acceptable, but the particular piano is not passing the desired aural tests; then adjust
the DOB during the tuning. The directions for adjusting the DOB before an FAC calculation are
below, and just after is the description of adjusting the DOB during the tuning.
- TO ALTER THE FAC CALCULATION
If the DOB is altered before calculating the FAC tuning, the tuning will be stored to memory with
the adjustments included in the tuning on that page of memory.
1)
Measure and store the FAC numbers (for more information see page 10)
