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

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

PRL-8721-LG0

702725245468

Regular price $178.19 USD
Regular price Sale price $178.19 USD
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Shipped within 1-2 business days.
Select Finish
Select Button Style

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

 

The PRL-8721 and PRL-8731 are left-handed sets of Locking RATIO® Calibrated Machine Heads for electric guitars 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

 

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

UPGRADE TO PREMIUM PLATED INVISOMATCH View full details
4.9
Rated 4.9 out of 5 stars
Based on 316 reviews
Total 5 star reviews: 302 Total 4 star reviews: 12 Total 3 star reviews: 2 Total 2 star reviews: 0 Total 1 star reviews: 0
99%would recommend these products
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316 reviews
  • JL
    jason l.
    Verified Buyer
    Reviewing
    6-In-Line Ratio Electric Locking Machine Heads Staggered Posts (PRL-9721, 9731, Select Finish and Button Style)
    I recommend this product
    Rated 5 out of 5 stars
    4 days ago
    ratio tuners

    this is a game changer..best tuners I've used

    Graph Tech Guitar Labs Ltd.
    2 days ago

    Thanks Jason, what guitar did you put them on? Dave D

  • MR
    Matt R.
    Verified Buyer
    Reviewing
    3+3 Ratio Electric Locking Machine Heads (PRL-8311, 8322, 8331, 8341, 8351)
    I recommend this product
    Rated 5 out of 5 stars
    1 week ago
    Great solution for my new PRS SE NF3

    I purchased a PRS SE NF3 a couple weeks ago. It is a great guitar, but wanted a locking tuner upgrade. I was originally nervous about the price combined with the "universal fit" thing. I took a chance and ordered these and they have been awesome. The universal plates fit great, although I did have to put in the plates for 3 and 4 together as they are butted up to one another. I was able to use the same screws, but new ones were also provided. I am attaching a photo.

    Regarding the "Ratio" feature, it is a game changer. I never expected it to feel different, more accurate, from other tuning heads. But these being geared to each string's thickness/tension is really effective.

    If you're on the fence, I hope this helps. This is a unique product with features I would love to see become more standard from premium guitar companies. I am not considering upgrading my Telecaster to Ratio tuners.

    Graph Tech Guitar Labs Ltd.
    2 days ago

    Thanks for the great review Matt. Some models by ESP (Bass), Schecter, Maton, Martin, and the Godin Connaisseur Acoustics are coming with RATIO... it's great to see. (and play!

  • MT
    Mark T.
    Verified Buyer
    Reviewing
    4+2 Ratio Electric Locking Machine Heads Mini Contemporary Button (PRL-8421, Select Finish)
    I recommend this product
    Rated 5 out of 5 stars
    1 week ago
    Worth the $$$

    I’m glad I threw frugality to the wind and bought these tuners. They really are a worthwhile upgrade. EBMM guitars are very stable tuning wise, but the Ratio heads make getting there so much easier!

    Graph Tech Guitar Labs Ltd.
    2 days ago

    Well said Mark! Dave D

  • AD
    Anthony D.
    Verified Buyer
    Reviewing
    6-In-Line Ratio Electric Locking Machine Heads (PRL-8721, 8731, Select Finish and Button Style)
    I recommend this product
    Rated 5 out of 5 stars
    1 week ago
    Great addition

    This was an easy swap to upgrade to locking tuners. Excellent quality and tuning stability seems rock solid so far.

    Graph Tech Guitar Labs Ltd.
    2 days ago

    Thanks Anthony! What guitar did you put them on?

  • SR
    Scott R.
    Verified Buyer
    Reviewing
    3+3 Ratio Electric Locking Machine Heads (PRL-8311, 8322, 8331, 8341, 8351)
    I recommend this product
    Rated 5 out of 5 stars
    2 weeks ago
    Ideal LTD/ESP solution.

    These Ratio tuners are the absolute best drop-in solution for LTD/ESP tuning issues. Simple and quick to install, without the adaptive templates, and the tuning results are exceptional. I use a strobe bench tuner, and these machine heads yielded the most accurate results that I've ever seen. Highly recommended.

    Installed on an LTD EC-1000 Deluxe, as shown in photo.

    Graph Tech Guitar Labs Ltd.
    2 days ago

    Thanks Scott, and thanks for the photo! Play On! Dave D