Piano Quality Control & Assurance 3

Question 1

A piano's repetition spring (in a grand action) is too weak. What symptom will the player experience?

Accepted Answer

Slow repetition — the hammer fails to reset quickly after a note

Answer

A weak repetition spring fails to hold the repetition lever in position, causing sluggish note repetition at fast tempos.

Question 2

What does 'hammer line' (or 'line of hammers') inspection verify in a grand piano QC process?

Accepted Answer

All hammer striking points are equidistant from the strings at rest

Answer

Hammer line inspection ensures every hammer travels the same distance to the string, producing even tone across the keyboard.

Question 3

In factory QC for upright pianos, which test specifically checks for buzzes and sympathetic vibrations?

Accepted Answer

Chromatic scale played at forte while technician listens and touches cabinet panels

Answer

Playing loudly while touching cabinet parts isolates which panel or component is resonating and causing unwanted buzzes.

Question 4

A piano exhibits 'double striking' — the hammer hits the string twice unintentionally. Which regulation point addresses this?

Accepted Answer

Back check distance

Answer

The back check catches the hammer after it rebounds; if set too far, the hammer can bounce back and restrike the string.

Question 5

During a soundboard inspection, a technician measures crown using a straightedge. What does adequate crown indicate?

Accepted Answer

The soundboard retains its upward arch, maintaining downbearing pressure on the bridge

Answer

Soundboard crown creates downbearing force on the strings via the bridge, which is essential for transferring string vibration efficiently.

Piano Practice Test