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 as needed. The guide emphasizes that correcting errors in partial changes can greatly enhance sound quality.
Understanding Partial Changes in Computer-Generated Tunings
All computer-generated tunings include partial changes, which are adjustments in the harmonics or partials used for tuning. These partial changes often contain errors, and by correcting these errors, the overall quality of the tuning can be significantly improved. The number of partial changes present in a computer-generated tuning depends on the specific system employed by an Electronic Tuning Device (ETD).
PCC Procedure for FAC Tunings
This section outlines the steps for utilizing the Partial Change Correction (PCC) feature on the Sanderson Accu-Tuner IV, specifically to address the three partial changes commonly found in an FAC tuning. The typical areas requiring correction are:
- Tenor: B2/C3
- Lower Treble: B4/C5
- Treble: B5/C6
Using the PCC Feature
The PCC feature is straightforward to operate on the Sanderson Accu-Tuner IV. To activate the correction, press and hold the Sto/Stretch button, then press RST/MSR. For further guidance, refer to the instructional video provided below.
Additional Uses of PCC
Beyond correcting partial changes, the PCC feature can be used to shift the entire tuning up or down by any desired amount. For instance, if you want to tune the entire piano sharper by 2.0 cents, start by selecting a memory tuning in the SAT, such as an FAC tuning stored in the memory. Navigate to C8, add 2.0 cents to the current setting for C8, and then press and hold Sto/Stretch followed by MSR/RST. This action transposes the tuning up by 2.0 cents, affecting all notes below C8 accordingly.
PCC and DOB: Their Roles in Piano Tuning
Overview of PCC Functionality
PCC (Partial Change Correction) is a universal feature that allows adjustments to be made to any note on the keyboard. When PCC is used, it modifies the stored tuning, and these changes are permanent, remaining in memory until further modification. However, the original tuning can be restored by applying PCC with the appropriate settings, effectively reversing previous changes.
PCC vs. DOB Adjustments
PCC and DOB (Direct Octave Beat) differ in their approach to tuning adjustments. DOB functions as a ‘layer’ type adjustment, sitting on top of the existing tuning without altering what is stored in memory. In contrast, PCC directly changes the tuning data saved in memory, making its effects permanent until actively changed.
Advantages of PCC Permanence
The permanence of PCC is advantageous because any corrections made to a tuning remain stored. When the same tuning is reused for the same piano, those corrections are already in place, streamlining future tuning sessions and reducing repetitive work.
Efficiency in Relocating Partial Changes
If partial changes are relocated to a lower position, completing the relocation and then using PCC to correct any resulting errors makes subsequent tuning faster and easier. All prior adjustments are retained, which increases efficiency for repeat use on the same instrument.
PCC for Bass Tuning Adjustments
PCC is particularly valuable for making permanent tweaks to bass tuning. Instead of relying on DOB, multiple PCC adjustments can be made to fine-tune the bass. These changes remain with the tuning, ensuring consistency across future tuning sessions.