Graph Tech Ratio Locking Machine Heads are designed to make tuning faster, smoother, and more intuitive by solving one of the biggest problems with traditional tuners: every string reacts differently to the same tuning adjustment. Standard machine heads usually use one gear ratio across all six strings, which means some strings feel too sensitive while others require more turning to reach pitch. Ratio tuners take a smarter approach by giving each string its own calibrated gear ratio, so every tuning key responds in a more consistent and predictable way.
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For a standard 6-string electric guitar set, the gear ratios are individually matched from low E to high E as follows: 39:1, 24:1, 20:1, 35:1, 20:1, and 12:1. This patented multi-geared system is engineered so that each string reacts evenly to tuning adjustments, with approximately a half-turn equaling a semitone and one full turn equaling about a full tone. The result is a tuning experience that feels natural across the entire guitar, making it easier to make small pitch corrections, switch to alternate tunings, or tune quickly between songs.
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The locking design adds another major performance advantage. By locking the string securely at the post, Graph Tech Ratio Locking Machine Heads help reduce string slippage, minimize excess wraps, and improve tuning stability. This is especially valuable for players who bend strings, use aggressive vibrato, perform live, record in the studio, or simply want their guitar to stay in tune longer. String changes are also faster and cleaner because the string can be pulled through, locked, tuned to pitch, and trimmed with far less winding.
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Another key benefit is easy installation. Many Ratio locking sets include Graph Tech’s InvisoMatch adapter plates (brushed Aluminim), which are designed to use existing screw mounting holes on many guitars. This allows players to upgrade their tuners without drilling new holes, helping preserve the look, value, and originality of the instrument. The plates also help keep the machine heads properly aligned for a clean, professional installation. InvisoMatch Plates can also be purchased in Gold, Nickel, Chrome and Black.
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Graph Tech Ratio Locking Machine Heads are ideal for players who want more control, better tuning accuracy, and faster performance-ready setup. Whether you are fine-tuning before a recording take, changing strings before a gig, moving between standard and alternate tunings, or upgrading a favorite instrument, Ratio tuners deliver a more refined and reliable tuning experience from the first turn of the key.
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Graph Tech PRL-8351-C0 Ratio Locking Tuners Chrome Features:
- Patented Ratio Gear Technology
- Each string has its own optimized gear ratio, giving players more consistent tuning response across all six strings.
- Calibrated Electric Guitar Ratios
- Low E to high E: 39:1, 24:1, 20:1, 35:1, 20:1, 12:1 for balanced tuning feel and improved accuracy.
- One Turn, One Tone Feel
- Designed so each string responds more evenly, making tuning faster, easier, and more predictable.
- Locking String Posts
- Locks the string securely in place to reduce slippage and improve tuning stability.
- Faster String Changes
- Less winding means quicker restringing, cleaner wraps, and less time spent getting the guitar ready to play.
- Improved Tuning Stability
- Helps the guitar stay in tune through bends, vibrato, hard playing, and performance conditions.
- Great for Alternate Tunings
- Makes it easier to move between standard tuning, drop tunings, open tunings, and other setups with more control.
- InvisoMatch Mounting System
- Allows many installations without drilling new holes, helping protect the instrument’s headstock.
- Clean Professional Appearance
- Hidden mounting plates and precise alignment give the finished installation a factory-quality look.
- Available in Multiple Styles
- Offered in popular configurations such as 6-in-line and 3+3 sets, with different finishes and button styles to suit a wide range of guitars
