4 String 2+2 Bass Ratio Y-Style Button (PRB-4220, Select Finish)
4 String 2+2 Bass Ratio Y-Style Button (PRB-4220, Select Finish)
PRB-4220-C0
702725245178
Couldn't load pickup availability
RATIO® patented gear technology
RATIO® - Calibrated Machine Heads incorporate different string gauges into the tuning equation.
From Low E to G - 36:1, 30:1, 20:1, 18:1.
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-4220 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: 35/64" (14mm)
String post diameter: 0.547" (13.9mm)
String post length to string hole: 1.030” (26.1mm)
Weight per single machine head: 1.86oz (53g)
Weight per set of four: 7.44oz (212g)
String diameter up to 0.98 gauge (or larger if taper-wound)
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
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 compatibility is essential.
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.
Click a picture to open the dimensions
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 50 patents and trademarks around the world.
- MLMichel L.Verified BuyerReviewing3+3 Ratio Electric Guitar Machine Heads (PRN-2311, 2341, please select finish and button style)I recommend this productRated 5 out of 5 stars1 week agoWorth it
made a huge difference on the bottom strings of my electric. I was use to see the tuning change by looking at the pegs :-)
- SNSteven N.Verified BuyerReviewing3+3 Ratio Acoustic Guitar Machine Heads Gold Finish. "45 Degree mounting screw" (GT-118-D0)I recommend this productRated 5 out of 5 stars1 week agoRatio tuners
smooth action , no lag. I put them on my Martins
- KWKristian W.Verified BuyerReviewing3+3 Ratio Electric Locking Machine Heads (PRL-8311, 8322, 8331, 8341, 8351)I recommend this productRated 5 out of 5 stars2 weeks agoGreat tuners
A bit expensive compared to competitors, but absolutely worth the extra money.
The only downside for me, was that the connection plates didn't match my original Kluson Waffle back.
- MCMarty C.Verified BuyerReviewing3+3 Ratio Electric Locking Machine Heads (PRL-8311, 8322, 8331, 8341, 8351)I recommend this productRated 5 out of 5 stars2 weeks agoLove These Tuners!
I have Graphtech tuners on my three guitars! They are the best of the best, in my opinion! These machine heads keep me in tune better than any tuners I’ve ever used! Worth every penny if playing in tune is a non-negotiable requisite for your playing satisfaction!
- JYJamie Y.Verified BuyerReviewing3+3 Ratio Acoustic Locking Guitar Machine Heads (PRL-8411, PRL-8441, Select Finish and Button Style)I recommend this productRated 5 out of 5 stars3 weeks agoBest ever
I put these on my acoustic and they feel very premium.