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.
- ATAndrew T.Verified BuyerReviewing7 Strings: 3+4 Ratio Electric Locking Machine Heads (PRL-8621, Select Finish and Button Style)I recommend this productRated 5 out of 5 stars21 hours agoThe best tuners
I had my Schecter Omen Elite 7 string for a while. But the tuners were some of the worst I’ve ever had. Hardly ever in tune, really picky and sticky when tuning. Decided to take a shot on these as an upgrade. They are excellent. The multiple ratios really helps with the large gauge strings, and they came in a 3L 4R set which was perfect. Along with the mounting plates they were a super easy install. Couldn’t recommend more. The only downside is that I had to order black mounting plates. So now I’ve got extra plates sitting around, but it’s hardly a big problem.
- JOJohn O.Verified BuyerReviewing3+3 Ratio Electric Locking Machine Heads (PRL-8311, 8322, 8331, 8341, 8351)I recommend this productRated 5 out of 5 starsYesterdayThese are precison tuners
Good job on the engineering and manufacturing!
- TMTy M.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 stars1 week agoPERFECT
GREAT FIT easy to install
- RTRobin T.Verified BuyerReviewing3+3 Ratio Acoustic Guitar Machine Heads (PRN-2411, 2421, Select Finish and Button Style)I recommend this productRated 5 out of 5 stars1 week agoLove them !
Very smooth movement and verry precise
- KBKhary B.Verified BuyerReviewing6 String 3+3 Bass Ratio Y-Style Button (PRB-6330, Select Finish)I recommend this productRated 5 out of 5 stars2 weeks agoColor me impressed...
After one of the posts on the stock tuners snapped on my Ibanez BTB806MS, I decided to give these a try. A bit pricey, but I was curious enough about them. I never really gave tuners a second thought besides weight, but after installing these and QUICKLY tuned up the strings, I don't know why I haven't tried these sooner. Holds tune, the smoothness of the turns is sublime...why am I gushing over something as mundane as tuner? Worth. Every. Penny.