Musicmaster/Duo-Sonic Gallery

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Tuning stability

Improved intonation

     Setting the intonation on a guitar requires positioning of the bridge saddles such that an open string (and its harmonic at the 12th fret) will sound the same pitch as the fretted octave at the 12th fret. If the fretted note is flat, move the saddle forward (towards the nut), and vice versa. Although some say you need a strobe tuner for precise intonation, any quartz tuner with a needle gauge will get you pretty close. Most people don't play chords past the 12th fret anyway.

     Unfortunately, perfect intonation can't be achieved, even if you use new strings that have been "broken in" and a nice strobe tuner, because the guitar is a tempered-scale instrument. (The Buzz Feiten tuning system is said to offer a solution to this, but that topic is well beyond the scope of this web page.) Intonation is even more difficult to set on a guitar with just three saddles: adjusting one string will affect another, and achieving the right balance (especially on the D-G saddle) is very difficult. Regardless of which method you try, keep in mind that if you change string gauges (or tune down sometimes), you'll probably end up having to re-set the intonation for the new tuning or string gauge. As much of a pain in the rear that setting intonation is, it's best to dedicate a guitar to one tuning and one gauge of strings only.


Bridge mods

Solution 1: Tune your G string slightly flat

     This idea was originally applied to the Fender Telecaster, which also originally had 3 saddles, and is easily adapted to the MM/DS. I first read this idea on Seymour Duncan's web page (Celebrity Tech Tip: Saddle Up Your Telecaster, by Jerry Donahue). By tuning your G string a few cents flat [see Dan Erlewine's book, How to Make Your Electric Guitar Play Great, for a much more detailed description], you take advantage of its tempered scale, and it will sound slightly more pleasing to the ear. I did this for a while before trying solution #3 below. When tuning or setting intonation, I tried to match the fretted "B" on the G string (4th fret) to the open B string. This solution requires no actual modification to your guitar and no parts to buy, so it can't hurt to try it. Let your ears be your guide.

Solution 2: Bridge modification without permanent changes
Contributed by Jay Christensen (August 2004)

"To improve the intonation on DS/MM guitars, replace the bridge string length/intonation screws and slowly twist/rotate the bridge saddle into correct intonation for its pair of strings -- bending the intonation screw! Save the original screws to allow the guitar to be returned to 'stock.' Here's my suggested step by step instructions:

  1. Set up your guitar (string-to-string distances, action heights, and intonation) using strings which have settled into place. Record all measurements. Temporarily lock only the bridge height screws in place with a mild strength locking compound or wood glue.
  2. Buy new intonation screws. Take a screw from the guitar to the hardware store to get the right diameter, thread size, and length. Use the shortest intonation screw possible; it needs to be fully threaded through the bridge saddle, but too much sticking out past the saddle after bending will look really strange and may even get in the way! If in doubt, buy several different lengths and buy at least 20 screws of each length to have plenty of extras to experiment with and spares left over afterwards (go to the store just once!). Brass is easier to bend than steel and may add mass and density to the bridge (think '53 Telecaster), while steel will be closer to original specs and appearance and harder to bend (but not impossible).
  3. Remove the old strings, replace the old intonation screws with the new ones, install new strings, tune to pitch, and make sure that all strings and bridge saddles are repositioned properly (see 1. above).
  4. Set the approximate intonation for each bridge saddle/pair of strings so that one string is the same number of cents flat as the other is sharp, i.e. "split the difference".
  5. Slowly twist / rotate the bridge saddle into correct intonation (which will bend the intonation screw!). Use needle-nose pliers as a twisting tool by opening the jaws approximately 1 inch and using the jaw tips to slowly "push" both bridge saddle ends simultaneously in opposite directions (gripping the saddle in the middle takes more force and can damage it). Slowly twist the saddle/bend the screw, check the intonation, and repeat until the intonation is correct for both strings. String tension should keep the saddle centered in position, but the intonation screw will take on a distinct zig-zag pattern! Usually, the two bridge saddles for the high E & B pair and A and low E pair will be rotated counterclockwise, while the saddle for the G and D pair will be rotated clockwise for a plain G string but counterclockwise for a wound string.
  6. If you can't get both strings in a pair correctly intonated, get one string correct and note how much the other is sharp or flat. Then straighten out the intonation screw or use a new one, and change the starting position of the bridge saddle on it (see 4. above) to compensate for the error: if one string was still flat, set the intonation for the pair to be more sharp before bending; if one string was still sharp, set the intonation for the pair to be more flat before bending. [Errors can be due to variances in how the bent screw stretches on one side while it compresses on the other, differences in the strings, etc.].
  7. If the intonation is correct for both strings and the screw was bent slowly in only one direction during the process, you are done for that bridge saddle! Repeat the above process for the other saddles.
  8. If the intonation is correct for both strings but the intonation screw was bent more than necessary, you may want to replace it to avoid metal fatigue. Mark the correct position of both saddle height screws on the bridge plate with something that can be wiped off, replace the intonation screw, and slowly ease the new one into position with a series of slow bends in the correct direction only.
  9. Do a final check on the intonation of all six strings.
  10. Play the guitar & have fun!
And here's my thoughts and experience on the process: I am not a metallurgist so I may be in error but I think metal fatigue results more from rapid bending, large bends, bending in opposite directions, and/or the number of bends. The way I do it, the brass intonation screws on my 1961 Duo-Sonic have been bent slowly in only one direction to minimize metal fatigue. I have had no problems since I intonated the guitar several years ago -- the screws are holding up just fine, the guitar remains essentially 'stock', and the intonation is just as good as with a set of the high-priced 'compensated' saddles. String changes are never a problem, and since I always use the same make, type, and size of strings, I avoid intonation adjustments which would weaken the screws."

I haven't yet tried this mod myself, but it seemed like too good of an idea to not share with anyone. Perhaps the best thing about this mod (other than the fact that it is completely reversible) is that you don't have to shim the neck to account for the larger diameter of Telecaster "compensated" saddles (see solution #3, below) relative to stock MM/DS saddles. Thanks, Jay!

Solution 3: Replace the saddles with a set of "compensated" saddles

     This idea was also developed for the Telecaster, and basically involves slanting the Tele's smooth brass "barrel" saddles slightly, with the adjustment screw hole drilled at a slight angle (about 7 degrees from the perpendicular direction). The first company I saw that offered "intonated" brass saddles was Vintique, an after-market/custom Telecaster parts supplier. All of their parts are top-notch quality, but unfortunately they're also higher-priced (the saddles kit was about $65). MannMade USA makes a similar part (TrueTone saddles; once cost about $40). I think their version was the one used on Fender's Danny Gatton Signature Telecaster. Stewart-MacDonald has since began offering a similar part (stock no. 5167, $14), although they require a minimum $30 order. Because the saddles are made of brass (which is about 10% more dense than steel), your guitar might have a noticeably brighter sound. The extra density of the brass saddles may just attenuate the lower frequencies more, causing a perceived increase in brightness, but I really haven't studied the physics enough to know for sure. As of 2002 the Wilkinson Adjustable Compensated Vintage Tele Saddles (stock no. 5072, $40) was also available from StewMac, but I have yet to try these saddles on any type of guitar. Finally, Giant Guitars recently began offering compensated saddles with beveled ends on the D-G saddle for a tighter, more compact saddle arrangement. I replaced the StewMac saddles on my late '50s MM-to-DS conversion with Giant Guitar's saddles in summer 2004.

     These compensated saddles have worked great on my Fender mutant ('56 Duo-Sonic body/'65 Mustang neck) and my late '50s Musicmaster-to-Duo-Sonic conversion (now with a proper bridgeplate from an early '64 Duo-Sonic). No drilling was required to get the adjustment screws to fit, either. The bridgeplate on my '65 Musicmaster II required some minor drilling, but it worked fine as well. A Tele's bridge saddle adjustment screws (#6 (6/32") pan-head machine screws) are slightly larger in diameter than those on stock MM/DS (4/40"), so I had to slightly enlarge the saddle screw adjustment holes on my bridge plate. I used a hand drill (for lower shaft velocity, and less chance of the bit skidding out of the hole) and braced the bridge plate between two pieces of wood, held together by a thick rubber band, so that I would be drilling into the wood. (Be warned that this type of clamp might flake off loose chrome on the bridgeplate.) You'll need a #28 (0.140") or ~9/64" cobalt heavy-duty bit, since you're drilling into metal. The end result looks pretty good, and the string spread (2 3/16") is almost identical to the stock saddles.

     Before you try this mod, there are several factors to consider. The diameter of Tele saddles is much larger than the diameter stock MM/DS saddles, so you may have to shim the neck to compensate (and the "ashtray" bridge covers used thru mid-'64 might not fit anymore). In addition, the new saddle adjustment screws were just long enough to allow intonation of the B and high E strings on my '65 Musicmaster II. Also, the Telecaster is a string-thru-body guitar, so the strings come over the saddles at a more severe angle than they would on a top-loading MM/DS. This means that although slots might not be required to keep the strings from sliding along the saddle of a Tele, you will probably have to file small grooves into the top of the saddle for use in a MM/DS. (Use the smallest triangle-profile file you can find, and remember you don't need to go very deep -- ~.010" or less will be plenty, even for the low E string. When you're done, lubricate the slot with graphite from a sharp pencil.) Other than that, I was able to set the intonation much easier than before, and it definitely brightened up the sound! This mod is also relatively non-invasive (although post-'64 bridge plates can't be returned to normal once you enlarge the holes). I didn't mind enlarging the holes on my '65 MM2's bridgeplate, since it already had a large spot where the chrome had flaked off and corroded the metal. If the bridgeplate on your guitar is in good shape, you might want to buy a another bridgeplate (new ones used to be pretty cheap, ~$25 from SmartParts until they went under) and save your original one.

     As far as celebrity endorsements go, I've seen a live photo of Liz Phair playing her red '60s Musicmaster II, and its bridge saddles were clearly angled (both photos © However, I don't know what brand the saddles were, or if they were just a custom job. Those photos were taken in summer 1999, a few months before I knew of Vintique's saddles and got the idea to try such angled saddles on my '65 Musicmaster II, so Liz's guitars were likely the first to be modified in this way. These angled saddles are also clearly on display on the back cover of her recent self-titled CD (this time on her faded white '60s Duo-Sonic II).

Solution 4: Replace the bridge entirely

     My red '50s Musicmaster came with a hardtail Strat-style bridge. This probably offers the ultimate intonation improvement (six fully adjustable saddles), and the through-body design will improve sustain. But even if this were an easy, non-invasive mod, I can't endorse it: I don't have the tools to precisely perform this mod, and I'm not sure I'd ever have the patience. (I eventually removed the hardtail Strat bridge and replaced it with a proper bridgeplate I found on eBay.) Anyway, assuming you can locate the replacement bridge properly (I was amazed to find that the one on mine was off-center by 1/16"), the key difference is string spread. A 25.5" scale Strat has a somewhat larger string spread at the bridge (the replacement on mine had a 2.25" spread) than a stock 22.5" scale Musicmaster (about 2 3/16"). In other words, the outer (E) strings risk being close to falling off the fretboard, or over the edge of the pickup polepiece rather than being centered on it. You might also consider a Fender Toronado bridge (also used on the Squier Musicmaster guitar), which is string-thru-body and has 6 saddles, and superficially resembles the bridge plate used on all post-'64 MM/DS guitars; because it's for a 24.75" scale guitar, it may be a better fit. (Check here for a description of the Toronado bridge installation.) Warmoth also offers narrow string-spaced hardtail strat bridges (2 1/8" spread) that might work here. At any rate, try this mod only if you're both well-equipped and brave to boot.

Solution 5: Permanently modify your guitar's bridge
Contributed by Darryl W. N. Murray (February 2009)

"I saw your site and thought I'd show you a simple bridge modification I did to the bridge by simply drilling 3 more holes and adding strat bridge saddles (I'd rather use the tele brass rod ones but haven't found any yet). I used a hand held Dremel motortool without taking the bridge off the guitar. Also I used one of the pointy abrasive bits to get the hole started then a normal drill bit that I just eyeballed to the adjustment screw diameter. Now the intonation is perfect. Enclosed are 2 pixs, of the bridge and one of my baby in her otherwise stock condition. Notice the weird angle on the hi E string, for some reason thats the only way I can keep it from moving around it looks odd but it works."

I haven't yet tried this mod myself. Although I could not recommend such a non-reversible mod (drilling extra holes) on a vintage Musicmaster or Duo-Sonic, if you have a steady hand, it would enhance the playability of a reissue Duo-Sonic. Thanks, Darryl!


     This page listed some solutions to setup problems faced by Duo-Sonic and Musicmaster owners. For general setup info applicable to most any guitar, check the official Fender setup guide. Several guitar repair/maintenance books have been published with information on this topic as well.