Graph Tech Ratio Machine Heads – Ultimate Control and Precision
RATIO® patented gear technology
RATIO® - Calibrated Machine Heads incorporate different string gauges into the tuning equation.
From Low E to G - 36:1, 30:1, 20:1, 18:1.
We balanced the gear ratios to each string simplifying the tuning process.
With RATIO®, a half-turn is a semi-tone!
Every string reacts the same to any tuning adjustment. Predictable, precise tuning, on every string.
The PRB-4400 is a right-handed set of RATIO® Calibrated Machine Heads for BASS that use a 4-in-line configuration.
Ratio's are the world's first machine heads using a double envelope gear design
with a hardened steel gear. Amazingly smooth and super strong.
