Adding a pull rod to compensate for cabinet drop

[Michael Hill]

I have a GFI Ultra. I have a common complaint related to cabinet drop. When I press A, but not B, string 6 goes a little flat. My biggest issue is when playing a major chord with A & F, the 5th of the chord is on string 6 and it goes flat just enough to make me cringe a little.

So I've decided to try adding an additional pull rod to the A pedal to bring string 6 back up to pitch.

I'm going to order the parts to try this but I'm not sure how the install will work. One idea was to install a new bell crank in line with string 6 on the A cross shaft. Another idea was to use the existing bell crank for string 5 and maybe bend the pull rod if needed.

Is bending a pull rod to route it to the changer an ok idea? And if so, are there any tips on how to do the bending?

Thanks in advance!

[Ron Pruter]

Should work fine. Have the rod come from the side of the bell crank toward the 6th string so you can keep the bending of the rod to a minimum. Also, before doing all that, try using a wound 6th string (Same gauge)It will greatly help cabinet drop. You will need to adjust for a longer throw. Mike, I work on steels here in Mesa. RP

[richard burton]

One problem with having a compensator rod like you describe is string hysteresis.

If you were to press the A pedal, string 6 would be nudged to its correct pitch , but if you then press the B pedal, then release it, all the time keeping the A pedal pressed, you will find that string 6 will now be sharp

[Jerry Overstreet]

Yes, you can use the same bellcrank to connect your pull rod for string 6 truing compensator as Ron states. Use the position with the least amount of change as it only takes a very few cents to true your tuning.

I've been doing this since the 90's on many different makes and designs of guitars. I've had no problems with this fix and never noticed the tuning problems that Richard mentions.

[Jon Light]

Richard Burton (who knows his stuff) may be talking about the same issue I had or it may be different -- my analysis is that it is a mechanical issue and not hysteresis.

If I am remembering the issue correctly --

-- with a raise compensator going from the A pedal to string 6, when I play strings 5 & 6 with the A pedal down, then depress the B pedal, then release the B pedal, the 6th string returns to an unacceptably sharp G#. It requires an extra stomp on the B pedal to return things to normal.

I abandoned the compensator. I loved the idea of it but could not overcome this quirk of the changer on both my Carter and Fessenden (and maybe Sho-bud?...can't recall). It has been documented enough here on the forum so that I know that it's not just me.

My choice has been a wound .024 6th string which reduces the detuning to around 2 cents.

[Jerry Overstreet]

I guess I've just been lucky then. This compensator pull is the same as any other string that you raise twice. I don't understand the issue.

[Earnest Bovine]

My choice has been a wound .024 6th string which reduces the detuning to around 2 cents.

I like wound 6th too (.022) for that reason and because it sounds better than a plain string. Downsides are that it makes the B pedal stiffer/longer, and it causes more cabinet drop than the plain string does.

[Earnest Bovine]

When I press A, but not B, string 6 goes a little flat.

I'm sure it happens when the B pedal is down as well. Adding an extra rod to raise string 6 won't help there, because string 6 is already raised. One solution would be to keep string 6 normally lowered a tiny bit, and have the A pedal release that lower.

[Steve Mueller]

Michael,
The problem you're having is called "floating the changer." It's common to most brands of steels. As noted, a .022W 6th will minimize cabinet drop and stay in tune better than a .020 plain. Never tried a .024W. Could be even better as long as it doesn't make the pedal too stiff or break more often.

[C. D. Maclean]

Michael
I have also experienced the torture you describe on the A plus F chord. My old LDG didn’t have the issue as the cabinet drop was negligible but when I moved to an MSA Legend it had to be dealt with. I would say just go ahead with your idea and see how you get on. Some notable players over here just put in the compensator and seem to get away with it. Personally, I experienced the ‘floating changer’ issue described and Mitchell at MSA confirmed that this is indeed an issue when you raise a raise and then lower it again.
My solution is the one that Earnest describes which I installed some time ago now and it completely cures the problem. I haven’t had to touch it since I got it to work. With no pedals down, my string 6 sits with a small lower on it. This is removed when I press A or RKL to offset the cabinet drop. It’s invisible in operation and I don’t have to think about it. However, I did have to buy a milling machine!
Cheers
Calum

[Jon Light]

......Never tried a .024W. Could be even better as long as it doesn't make the pedal too stiff or break more often.

One reason I went back to a plain string a couple of times and tried to make the compensator work is that the G#>F# lower with a wound string is an extremely long lever throw. The .024 is for the purpose of shortening the throw a little bit. Breakage has been a non-issue, even with a whole step raise on the B6 Uni pedal.
It is a 12 string with yet another B pedal pull on string 11 and I do wish it was an easier touch but I've lived with it for a number of years.

[Eric Watts]

Jerry could you post a picture of how you use the same bell crank and add a rod? That would really be helpful in understanding how you overcame the issue.

[Jerry Overstreet]

Hi Eric. I use a 3rd bell crank working on the A pedal 5th string to true the 7th string lower as well with pedals down. You can see that extra crank in this photo.

I used the same crank for both the 7th string comp and the 6th string comp working off the A pedal. I believe the 6th string truing comp is at the one next to the axle. [I don't have this guitar now and the one I'm playing is elsewhere.]

You could do the same with the bell crank that pulls the 5th string off the A pedal if you don't have an extra one. Just use the position with the least amount of change. Most guitars will tolerate a slight rod angle. Depending on the design, installing the rod from the other side of the bell crank, such as Mullen or in this case the MCI, keeps the alignment.

I run a rod through the 6th string changer raise scissor with the least amount of travel and connect it to the position I noted above. It only takes a few cents to true it back to neutral...and it only comps when you use the A pedal alone. Using the B pedal of course has more change and goes beyond what the comp does so there's no interference there. Since both of these compensators only bump the tuning a few cents, there is negligible feel on the A pedal.

It's the same mechanical action as any double raise such as the 4th string where you might raise it a half tone with a lever and a whole tone with the C pedal.



I know some people here say they have problems with the string not returning correctly in certain situations but I've not experienced that. It completely cured the condition I had on a particular guitar back when and I've installed it on all my subsequent guitars, including the Universals, I've owned.

I'm not going to get into that argument. All I can say is it solved the detuning issue perfectly for me and I wouldn't be without it.

[Willie Sims]

I;M WITH JERRY,ON THIS TOPIC , THE A PEDAL DONT PULL THE 6 STRING .IT HOLD'S IT IN TUNE,WHEN YOU RELEACE B PEDAL,YOU NEED A LITTLE SLACK IN SIX STRING TUNNING NUT,OR IT WILL COME BACK SHARP,
I COULD BE WRONG,BUT MINE WORK'S GOOD.

[Eric Watts]

Simple solution Jerry!! Very nicely done and thought out.. Thanks for the picture and explanation.

[Michael Hill]

OP here. Thanks everyone for all the feedback and discussion on this issue.

I installed a new pull rod today. String 6 raise to the existing bell crank for the A pedal string 5. The install was so simple. It took maybe 5 minutes to install and 1 minute to dial in the tuning. I didn't even turn the guitar over.

I played for a while and so far I'm really happy with the results I'm getting. A + F chords are ringing truer than ever before!

[Jerry Overstreet]

...another benefit....I noticed it right away when I first installed this years ago....you don't have to tune that F note so flat. Glad you're finding this beneficial.

As Willie stated, yes, there must be some slack in the system since there is so much going on with the 6th string, particularly if you lower it a whole tone and/or have a split on it.

[Geoff Noble]

When I first bought my MSA Legend Mitchell had put the compensator rods on the A pedal, I experienced the same problem highlighted in this thread, i.e. on release the G# being sharp.

I re-rodded a single compensator rod from the F lever onto string 6 and this worked much better for the AF combination. I found string 3 pretty much OK without the compensator.

Every couple of months I experience a slightly sharp G# on string 6, if I lube the changer this fixes it.

Probably worth mentioning that my Legend is a Uni and has the E's on the right, so my F lever is RKL. don't know if the shorter distance to the changer is relevant.


C.D. Mcleans fix is pretty innovative and works well for him. Calum also has a 12 string Legend extended E9, his E's are on the left and have a longer rod length. I believe Calum tried my fix and it didn't work for him. It is also different in that it is a carbon fiber body with a wood finish over the carbon fiber.