Ratio by Graph Tech Model # 4221-C0 (23:1 to 48:1) Bass 2X2 F Style
Ratio by Graph Tech Model # 4221-C0 (23:1 to 48:1) Bass 2X2 F Style
PRB-4221-C0
702725244690
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RATIO® patented gear technology
RATIO® - Calibrated Machine Heads incorporate different string gauges into the tuning equation.
From Low E to G - 48:1, 36:1, 25:1, and 23:1.
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-4221 is a right-handed set of RATIO® Calibrated Machine Heads for BASS that use a 2 x 2 configuration.
In order to achieve higher gear ratios, Ratio are the world's first machine heads using a double envelope gear design with a hardened steel gear. Amazingly smooth and super strong.
Gear ratio: unique for each string position - one turn-one tone
Peg holes diameter required: 0.720" (18mm)
String post diameter: 0.547" (13.9mm)
String post length to string hole: 0.807” (20.5mm)
Weight per single machine head: 3.5oz (99.3g)
Weight per set of four: 14oz (397g)
String diameter up to 130 gauge
Includes 4 machine heads, mounting screws and bushings
Invisomatch Adapter Plates
InvisoMatch® Adapter Plates offer the easiest solution for installing RATIO® Tuned Machine Heads on your guitar
Simply select the installation plate design that matches the screw/pin hole location of your factory installed machine heads. You’ll be up and running within minutes, perfectly installed and aligned. Stay classy you axe master.
For stunning accuracy and response... upgrade to RATIO® Machine Heads with it's patented Multi-Geared Tuning Technology. The new standard in tuning.
No drilling, perfect alignment, fast installation!
The alignment of the machine heads is perfect, no holes to drill or fill, ideal for vintage instruments. Premium finishes are available for order, including chrome, nickel, black, and gold. Additionally, each set of RATIO® Tuners comes with four complimentary brushed aluminum InvisoMatch® Adapter Plates.*
*Each set of Graph Tech RATIO® Machine Heads includes four sets of brushed aluminum InvisoMatch® Adapter Plates. These plates are not included with bass or open back tuners. For a customized appearance, are available in finishes such as chrome, black, nickel, and gold.
Find your InvisoMatch® Adapter Plates fit (download the guide!)
Please note that our InvisoMatch® Adapter Plates list is regularly updated. Before placing your order, ensure the selected plate matches your guitar's specific model and variation.
* Some guitars may have different configurations, so double-checking is essential.
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Graph Tech has created some of the world's most recognized products and brands in the music industry
The list of industry firsts include the world's first self-lubricating nut in 1983, String Saver Saddles the first saddle to drastically reduce string breakage, TUSQ man-made ivory, and Ratio machine heads.
Graph Tech has over 65+ patents and trademarks around the world.
- GGilbertReviewingRatio by Graph Tech Acoustic 3+3 Guitar "45 Degree mounting screw"I recommend this productRated 5 out of 5 stars3 weeks ago5 Stars
Top grade equipment, second set I have purchased, and it won't be my last set.
I will be upgrading my preformance guitar next !
- MBMarc B.Verified BuyerReviewingRatio by Graph Tech Model # 8311-C0 (12:1 to 39:1) Electric Locking 3x3I recommend this productRated 5 out of 5 stars3 weeks agoDo it!
Replaced rubbish Gotoh locking tuners with these. Wish I had just spent that little bit extra to begin with. Great quality, massive improvement
- TCTony C.Verified BuyerReviewingRatio by Graph Tech Model # 8311-C0 (12:1 to 39:1) Electric Locking 3x3I recommend this productRated 5 out of 5 stars1 month agoLocking Ratio Tuners
Superb tuners, love ratio locking tuners, best on the market.
Thanks GraphTech!!
- RFRob F.Verified BuyerReviewingRatio by Graph Tech Model # 9721-C0 (12:1 to 39:1) Electric Locking 6 in-Line StaggeredI recommend this productRated 5 out of 5 stars2 months agoReplaced My Sperzel Tuners with These
Fantastic Tuners. Replaced my Sperzel Tuners with the Ratio Staggered Tuners. Fit right in with the Sperzel adapters. No extra drilling necessary.
- CSChuck S.Verified BuyerReviewingRatio by Graph Tech Model # 8411-C0 (12:1 to 39:1) Acoustic Locking 3x3I recommend this productRated 5 out of 5 stars2 months agoRatio Tuner
Extremely happy with the ratio tuners this is my third set and I will continue to buy as needed wonderful support from GRAPH TECH as well