Ratio Electric Locking Machine Heads 6 in-line (select finish and button style) - Graph Tech Guitar Labs Ltd.
6-In-Line Ratio Electric Locking Machine Heads (PRL-8721, 8731, Select Finish and Button Style) - Graph Tech Guitar Labs Ltd.
Ratio Electric Locking Machine Heads 6 in-line (select finish and button style) - Graph Tech Guitar Labs Ltd.
Ratio Electric Locking Machine Heads 6 in-line (select finish and button style) - Graph Tech Guitar Labs Ltd.
Ratio Electric Locking Machine Heads 6 in-line (select finish and button style) - Graph Tech Guitar Labs Ltd.
Ratio Electric Locking Machine Heads 6 in-line (select finish and button style) - Graph Tech Guitar Labs Ltd.

6-In-Line Ratio Electric Locking Machine Heads (PRL-8721, 8731, Select Finish and Button Style)

PRL-8721-C0 2 reviews
Select Finish
Select Button Style

SCIENCE BEHIND RATIO:

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.

RATIO Machine Heads explanation video

 

Description:

The PRL-8721 and PRL-8731 are a right-handed sets of Locking RATIO® Calibrated Machine Heads for electric guitar that use 6-in-line tuners.

It has a two pin casing that can be used as is, or with our Patented InvisoMatch Mounting Plates [opens in new tab].

4 different sets of InvisoMatch mounting plates in brushed aluminum are included to make installation on most guitars fast and accurate by using your existing screw mounting holes.

 

6-in-line tuners set  Ratio Tuned Machine Heads: The New Standard In Tuning Technology

 

Specification:

Gear ratio: unique for each string position - one turn-one tone
Peg holes diameter required: 13/32" (10mm)
String post diameter: 0.236" (6mm)
String post length to string hole: 0.910” (23mm)
Weight per single machine head: 0.083lbs (38g)
Weight per set of six: 0.496lbs (225g)
String diameter up to 72 gauge
Includes 6 machine heads, mounting screws and bushings
Includes complimentary 4 sets of aluminum mounting plates

GUIDES:

Staggered Ratio Measurements.pdfRatio Installation Guide.pdfRatio Installation Guide Video

REVIEWS:

Moss Hart

Reviewed in the United States on February 15, 2020

Amazon Verified Purchase

 

Customer Reviews
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CB
16 Jun 2022
Chris B.
Canada Canada
I recommend this product

Exceeded Expectations

These tuners are amazing. This year I switched from using Floyd Rose fine tuners to fixed bridge guitars with regular machine heads and doing an ultra-accurate tuning job with regular machine heads just hasn't been possible. After searching for "fixed bridge fine tuners", I learned about gear ratios and locking tuners, and specifically these Graph Tech Ratio locking tuners. After installing these, I noticed an immediate improvement in tuning accuracy and stability, fine tuning is now possible, and changing strings has never been easier with the locking feature (I'm actually looking forward to it next time). Installation on my Jackson JS32T Warrior was very easy and required no drilling thanks to the mounting plates. I can't imagine playing another guitar without these.

Graph Tech Guitar Labs Ltd. 6-In-Line Ratio Electric Locking Machine Heads (PRL-8721, 8731, Select Finish and Button Style) ReviewGraph Tech Guitar Labs Ltd. 6-In-Line Ratio Electric Locking Machine Heads (PRL-8721, 8731, Select Finish and Button Style) Review
CL
10 May 2022
Chris L.
United States United States
I recommend this product

Solid as a rock!

I installed these on my Tele and tuning is so easy and quick on the fly! I rarely have to tune it anymore, but when I do, it’s in slight increments and it stays put!

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