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.
- DSDes S.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 stars3 weeks agoBest Tuners in The World
Absolutely love ratio tuners. The way all tuners should be. The price may put some people off but really they are competitvely priced against big name tuners like Grover or Gotoh and you're lucky if they are 18:1 ratio.
I've replaced most of my collection with Ratio tuners and still love my earlier special order for my 12 string acoustic. Stays in tune so well. and now I enjoy picking it up and playing without having to re-tune every time.
Great customer service and regular updates after placing order.
- LBLarry B.Verified BuyerReviewing3+3 Ratio Electric Locking Machine Heads (PRL-8311, 8322, 8331, 8341, 8351)I recommend this productRated 5 out of 5 stars3 weeks agoSimply the best!
TSIA
- CTcurtis t.Verified BuyerReviewing3+3 Ratio Acoustic Open Back Tuners (PRN-3411, Select Finish)I recommend this productRated 5 out of 5 stars3 weeks agoAcoustic 3+3 for Guild D55
I have installed Ratio tuners on other guitars and with the new Guild, it was the first change I decided to make. Much more precise than the OEM Gotoh SE700. BUT, I have not installed these tuners yet as I am waiting for the local luthier to change the nickel finish. I wanted these tuners black, as I have had on the other closed Ratios. Maybe a gentle nudge to offer this finish. The screw holes will have to be filled in as the included screw for the Ratios are a bit less robust than the Gotoh. Still, I am pleased to know that these will soon be installed, along with the TUSQ bridge pins, presentation style, with Paua inlay.
Nice work from good people!!
- JRJesus R.Verified BuyerReviewing5 String 3+2 Bass Ratio Y-Style Button (PRB-5320, Select Finish)I recommend this productRated 5 out of 5 stars4 weeks agoExcellent product
Graphtech is the standard for these parts and the customer service and attention is second to none. Thank you so much for all your help and for extremely fast service.
- RRRobert R. M.Verified BuyerReviewing3+3 Ratio Acoustic Open Back Tuners (PRN-3411, Select Finish)I recommend this productRated 5 out of 5 stars1 month agoExcellent addition to my 000
Very accurate and hold tune over time.