Piano Quality Control & Assurance 4

Question 1

A QC technician finds that several treble notes have too much sustain even with the damper pedal not engaged. What is the most likely cause?

Accepted Answer

Dampers in the high treble are missing — this range is intentionally undamped by design

Answer

By design, grand pianos typically have no dampers above approximately F6 because strings in the high treble are short enough to decay naturally.

Question 2

Which measurement tool is used to check the consistency of key dip during regulation QC?

Accepted Answer

Dip block (key dip gauge)

Answer

A dip block is a small block of precise thickness placed beside the key to measure whether the key descends the correct distance.

Question 3

A piano string breaks shortly after the instrument leaves the factory. Which QC failure is most directly implicated?

Accepted Answer

Incorrect string gauge or improper tension relative to speaking length and pitch specification

Answer

String breakage is most often caused by over-tensioning relative to the string's gauge and speaking length, a manufacturing or stringing error.

Question 4

What does 'down-bearing' on a piano bridge refer to?

Accepted Answer

The downward pressure exerted by strings on the bridge, transferring vibration to the soundboard

Answer

Down-bearing is the angle-created downward force of strings pressing on the bridge, which is critical for efficient soundboard coupling.

Question 5

During factory QC, what does a 'playing-in' or 'run-in' procedure accomplish for a new piano action?

Accepted Answer

Wears in the felt and leather contacts to reduce initial stiffness and even out touch feel

Answer

Playing in a new action compresses and conditions the felt and cloth parts, stabilizing touch weight and reducing initial friction.

Piano Practice Test