Robert Conrad, Registered Piano Tuner/Technician, Tucson, AZ
Understanding SAT IV Light Behavior The SAT IV is highly sensitive and detects everything, including false beats and other types of “noise” that are produced by vibrating strings. This sensitivity can sometimes result in the SAT IV’s rotating lights appearing fuzzy, unstable, or difficult to use when tuning certain notes. The presence of false beats…
The Double Octave Beat (DOB) feature has undergone significant changes since its initial introduction. Originally, the DOB range was limited to +/- 2.0, which placed constraints on treble tuning flexibility for technicians. Early Limitations of DOB When DOB was first implemented, its range was set at +/- 2.0. With this configuration, the maximum DOB setting…
Refining FAC Tunings: Procedures and Best Practices This document provides a detailed guide for refining FAC tunings using the AccuTuner IV, emphasizing recommended settings and step-by-step procedures to achieve accurate results. It introduces the “A Multiplier Default” parameter, advises setting it to 0.8 for optimal double octave contraction, and explains how midrange stretch adjustments can…
Lowering the tenor partial change to G#2/A2 results in a full 2-octave (A2-A4) range with all notes within that range using their 4th partials for the tuning. Not having any partial changes within the A2-A4 range, makes the tuning more accurate by eliminating even the possibility of a partial change error between A2-A4. In the treble, using the 1st partial instead of the 2nd @ A5 makes determining and tweaking the treble stretch easier.
This post explains the process of correcting partial changes in ‘computer generated’ piano tunings, specifically using the Partial Change Correction (PCC) feature on the Sanderson Accu-Tuner IV. It details the typical partial changes found in FAC tunings and provides step-by-step instructions for using the PCC feature to improve tuning accuracy and adjust the overall pitch…
Start by setting the SAT’s ‘Up or Down Memory Storage’ to DOWN. The STO/MEM + Note UP or DOWN command sets the direction the SAT will automatically go, after a note is stored. Press BluShift and then STO/MEM to store the settings for B2, A#2, and A2. (Contains button pressing video).
When using the A2-A4 range for tuning a 2-Octave Temperament, all the notes within that 2 octave range need to use their 4th partials. This eliminates any possibility of a partial change error in that A2-A4 range. (Contains button pressing video).
The need for this tweak has been around for some years now, but it should be used whenever using an FAC tuning. (Contains button pressing video).
We need to know exactly where the 4th P of A4 is so we can be sure the FAC tuning is tuning A4 to @ A440.
There are a number of ways, when using an AccuTuner, to tune to non standard pitch. PCC is one of the easiest and most versatile. When PCC is used for tuning to non standard pitch, make note of the PCC adjustment so it can be reversed when the tuning is finished.
Using a sequence is a great way to quickly tune and make aural checks before committing to the complete tuning. (Contains button pressing video).
All computerized tunings have partial changes and those partial changes may contain an error. Correcting these errors can improve the sound of the tuning. This procedure will show how to correct the three FAC partial changes when using an AccuTuner SAT IV. But before correcting the partial changes, consider lowering the tenor partial change from…
This Partial Change Correction (PCC) feature is relatively new to the SAT IV’s programming. So if your SAT doesn’t seem to be responding to the STO + MSR command it’s program may need to be updated. Being able to correct partial changes is unique to the AccuTuner. An FAC tuning has fewer partial changes (3) than any other tuning system, and yet it is the only device capable of correcting them. (Contains button pressing video).
This post is part of a series on working with an FAC tuning. There are a number of tweaks that can be done to further fit an FAC tuning to the piano, before changing the F number.
Programming a custom over pull is so easy it’s not worth making a video of it. The custom over pull is ‘activated’ just like the regular pitch raise feature, but instead of rolling off onto the BlueShift, after MSR stops the lights, roll off onto the Green Shift. Rolling off on to the GREEN shift activates he Custom Over Pull and uses the amounts stored on Page 123.
DOB allows us to easily stretch or contract a template or tuning stored in the SAT.
Tweaking the treble stretch in an FAC tuning is a great way to ‘customize’ a tuning.