4 String 2+2 F-style Bass Ratio - Chrome (PRB-4221-C0)
4 String 2+2 F-style Bass Ratio - Chrome (PRB-4221-C0)
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 Mounting Plates
InvisoMatch Mounting Plates for RATIO Tuned Machine Heads are the easiest approach to 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
With InvisoMatch mounting plates you will reduce the time to install RATIO machine heads to well under 15 minutes.
The alignment of the machine heads is perfect, no holes to drill or fill, ideal for vintage instruments.
Four sets of brushed aluminum InvisoMatch mounting plates come free with every set of Ratio Tuners.
Premium finishes including chrome, nickel, black and gold are available for order.
“After reading some reviews and seeing the ads, I decided to try a set of Graph Tech’s ratio tuners on my American standard Strat. The tuners arrived and I was very pleased with the quality and finish. Installing the tuners was a breeze using the included InvisoMatch plates — no need to drill any holes in my beloved Strat and the performance of these tuners is outstanding!"
"Tuning becomes incredibly easy and holds tune even when using the tremolo bar. I would highly recommend these as a great upgrade to any guitar and will be telling my customers what a great addition they would be for very stable and easy tuning.
Thanks, Graph Tech for a great product.!
Jay Langan / Magdon Music / guitar sales/ guitar tech
Click a picture to open a PDF file with the dimensions.
- JAJAMES A.Verified BuyerReviewing3+3 Ratio Lefty Electric Locking Machine Heads Contemporary Button (PRL-8311-L, Select Finish)I recommend this productRated 5 out of 5 stars1 month agoThe Best Product Ever!
I love the quality and craftsmanship of these tunners.
- SSStephen S.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 stars2 months agoLove these tuners!
I just installed GraphTech locking ratio tuners on my fifth guitar and they are, as usual, fantastic. The truth is, once you've tried these tuners, there is just no going back.
- PTPeter T.Verified BuyerReviewingRatio Tune-a-Lele Ukulele Tuners (4 pcs)I recommend this productRated 5 out of 5 stars2 months agoGreat friction peg replacements for old ukes!
They’re great - very light! I’ve used them before to replace friction peg tuners on old ukes with positive outcomes. Recommended!
- TMTy M.Verified BuyerReviewing3+3 Ratio Electric Locking Machine Heads (PRL-8311, 8322, 8331, 8341, 8351)I recommend this productRated 5 out of 5 stars2 months agoTuners
These work well, I did not need the additional gold plates
- GYGeorgy Y.Verified BuyerReviewing7 Strings: 7-In-Line Ratio Electric Locking Machine Heads Staggered Posts (PRL-9721-x7, PRL-9731-x7, Select Finish and Button)I recommend this productRated 5 out of 5 stars2 months agoPerfect pitch black (see what I did here?)
Best tuners on the market, no contest, competition is not even close.
Quality on par with the best of the best, functionality is better.
Used 7 string set for B standard tuned (13-64 strings) Jim Root Jazzmaster and skipped number 4 tuner (d string)
So I installed 7-6-5-3-2-1. I could use #4 tuner for 13 gauge string, but because it’s staggered it’ll be taller than #2 tuner post.
I find most benefit of ratio tuners are on wound strings so you don’t have to do 1/360th turns on thick gauge anymore.
Installation took like 3 minutes on top of restring, black fender plates = no drilling and great angle behind nut due to ever so slightly reduced post height.
2 main downsides of ratio tuners:
1. Price bites.
2. You want them on ALL YOUR GUITARS after trying once. Both downsides combined get pricey real fast.
Only guitar I wouldn’t install ratio tuners is one with evertune bridge. Regular lockers are enough there.