Ratio by Graph Tech Model # 3422-N0 (12:1 to 39:1) Acoustic 3x3

A Must Have!

I needed to replace a set of open back Grover tuners on my 2011 Keb Mo Bluesmaster. I decided to try the Ratio Graph Tech tuners. I've been playing professionally for over 50 years, with a degree in Jazz Guitar Performance. I highly recommend these tuners if you need to upgrade your instrument! I wish I had thought up this design, it's GREAT! The footprint is essentially the same as the Grover tuners, as were the ferrules and tuner shaft, so there was no need to drill and fill the mounting holes or ream out the headstock. I did have to file the ends of the 2nd and 5th string plates as there was some very minor interference, but I would estimate I only removed about 1/64" on each "ear". Overall an easy installation. I found a noticeable improvement in tuning the guitar. The number of string wraps around the posts are the same as with "conventional tuners". I'm so impressed with the Ratio tuners that I will be replacing the tuners on my other Gibson Custom Shop acoustics which currently have either Grover or Waverly "open back" machines. Thanks Graph Tech!!!

Changing the very simple and poor quality standard machine heads on an Ibanez acoustic guitar.

After successfully installing the new tuners, it is now a lot of fun to play the guitar and, above all, it is now very easy and precise to tune the guitar. When installing the new machine heads, the original mounting sleeve could still be used. It was only necessary to drill out the rear hole in the headstock from 6 mm to 6.4 mm using a countersink. The holes for the fastening screws could also be used. To be on the safe side, however, all the old holes were sealed with wooden pins (toothpicks) and wood glue and re-drilled with a 0.5 mm offset.

The Best Machine Heads I have ever had. 🎸