RATIO® patented gear technology
RATIO® - Calibrated Machine Heads incorporate different string gauges into the tuning equation.

From Low E to High E 39:1, 24:1, 20:1, 35:1, 20:1, 12:1.

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 PRN-3424 is the right-handed set of open RATIO® Calibrated Machine Heads for electric guitars that use 3 3 side tuners.

Please note that our retro tuners are made to a vintage specification (for 11/32” peghead holes) and will not be a direct replacement for a modern tuner. Please check the specifications below.