Unwound 6th string tension/tuning issue?

[Jeremy Glasgow]

Hi all,

Hoping someone here may be able to give some advice regarding the issue I'm having with my 6th string. For reference, I have a 2023 Mullen Discovery with GHS Boomers, unwound 6th string. I believe this is what the guitar came with.

For whatever reason, my 6th string is really tricky to get in tune and never truly feels in tune. I'm not sure how to describe the problem, but when tuning against the 8th string harmonic, it feels like it has less 'landing space' to hit the correct pitch. Tuning until the harmonic 'beats' go away is more so getting it close enough, rather than actually in line.

I do not have this issue with my 3rd string, and noticed that the 6th string travels far less (looking at the changer) than the 3rd string. Is this by design or do I need to adjust the stop? I've run through the overtuning guide stickied here, but I'm not totally confident making adjustments to the undercarriage. I've also tried detuning the open string, backing off the nylon tuning nut, retuning the open string, and retuning the nylon nut so the B pedal is to pitch but haven't had much luck.

Anyone have any advice? Thanks in advance!

[Richard Sinkler]

Did you switch from a wound to unwound string on your 6th string?

[Jeremy Glasgow]

Did you switch from a wound to unwound string on your 6th string?

It came with an unwound string, and that’s what I’ve got on it now. I’ve tried a wound string but it didn’t help much, and I mostly read folks saying to use whichever it came with

[Ian Worley]

... For whatever reason, my 6th string is really tricky to get in tune and never truly feels in tune. I'm not sure how to describe the problem, but when tuning against the 8th string harmonic, it feels like it has less 'landing space' to hit the correct pitch. Tuning until the harmonic 'beats' go away is more so getting it close enough, rather than actually in line.

I do not have this issue with my 3rd string, and noticed that the 6th string travels far less (looking at the changer) than the 3rd string. Is this by design or do I need to adjust the stop? I've run through the overtuning guide stickied here, but I'm not totally confident making adjustments to the undercarriage. I've also tried detuning the open string, backing off the nylon tuning nut, retuning the open string, and retuning the nylon nut so the B pedal is to pitch but haven't had much luck...

Your description doesn't provide a real clear picture of the specific problem you're having. Not sure what you mean by "landing space", open and raised pitches are absolute, even though they will typically vary a few cents because of cabinet drop and "hysteresis". Tuning the open note to the correct pitch at the keyhead is very straightforward, is your issue with the stability of the open G#? Is the issue related to that open pitch changing after you engage and release the B pedal? If so, is it consistent or just random? Is it something to do with the raised A note? Or does the open note end up sharp after you tune the nylon for the B pedal? Does the nylon just sort of stop raising the pitch at some point? What specific actions cause the issue to arise?

There are a several common things that can cause problems here but it's just a guessing game without a clearer description of the problem and how it manifests. It could be an actual mechanical issue within the changer, something binding or lacking proper lubrication. The most common and likely would be simple over-tuning. Correcting an over-tuning issue typically doesn't require a lot of adjustment, usually it's just a matter of backing off a stop screw on the affected pedal or lever, and possibly re-adjusting pedal or lever position once it's sorted out. How to make those adjustments varies a bit from builder to builder but it's usually fairly straightforward.

If you're absolutely certain over-tuning is not the issue, it could be something as simple as a stripped B pedal nylon tuning nut on string 6.

Another common issue would be a too-loose lower return spring, allowing the lowering scissor to lift off the stop before the string has reached the desired pitch. This creates a sort of tail-chasing situation where the changer mechanism begins lowering and raising at the same time toward the end of the pull so the raised pitch is very unstable. You'll be able to see this if, when you engage the B pedal, the lowering scissor begins to lift off the stop and stretch the lower return spring mid-pull. If so you'll need to tighten the return spring if adjustable, or shorten it to increase its tension.

To answer your question about the differing length of the two pulls on 3 and 6, this is expected and is based on the diameter and relative tension of the two strings. Smaller strings require a longer pull. Modern guitars can compensate with different leverages between the bell cranks and changer to balance the pulls so they start and end at the same time. Because of its small diameter core, using a wound string on 6 will lengthen that pull so the amount of movement in the pull rods are similar, but if your guitar is currently set up for plain 6th string it would typically require some adjustment to the rodding to get the pulls timed correctly again.

[Lane Gray]

If you're noticing that it's just finicky, that's because the thicker the core of the string is, the faster it responds to tension changes, and unwound strings are all core. That 0.022P is, mechanically speaking, the fattest string on the guitar, since even the 0.038 is actually an 0.012 (with 0.013 windings, 13 twice, plus the core).

And yes, it'll have the shorter pull.

[Jeremy Glasgow]

... For whatever reason, my 6th string is really tricky to get in tune and never truly feels in tune. I'm not sure how to describe the problem, but when tuning against the 8th string harmonic, it feels like it has less 'landing space' to hit the correct pitch. Tuning until the harmonic 'beats' go away is more so getting it close enough, rather than actually in line.

I do not have this issue with my 3rd string, and noticed that the 6th string travels far less (looking at the changer) than the 3rd string. Is this by design or do I need to adjust the stop? I've run through the overtuning guide stickied here, but I'm not totally confident making adjustments to the undercarriage. I've also tried detuning the open string, backing off the nylon tuning nut, retuning the open string, and retuning the nylon nut so the B pedal is to pitch but haven't had much luck...

Your description doesn't provide a real clear picture of the specific problem you're having. Not sure what you mean by "landing space", open and raised pitches are absolute, even though they will typically vary a few cents because of cabinet drop and "hysteresis". Tuning the open note to the correct pitch at the keyhead is very straightforward, is your issue with the stability of the open G#? Is the issue related to that open pitch changing after you engage and release the B pedal? If so, is it consistent or just random? Is it something to do with the raised A note? Or does the open note end up sharp after you tune the nylon for the B pedal? Does the nylon just sort of stop raising the pitch at some point? What specific actions cause the issue to arise?

There are a several common things that can cause problems here but it's just a guessing game without a clearer description of the problem and how it manifests. It could be an actual mechanical issue within the changer, something binding or lacking proper lubrication. The most common and likely would be simple over-tuning. Correcting an over-tuning issue typically doesn't require a lot of adjustment, usually it's just a matter of backing off a stop screw on the affected pedal or lever, and possibly re-adjusting pedal or lever position once it's sorted out. How to make those adjustments varies a bit from builder to builder but it's usually fairly straightforward.

If you're absolutely certain over-tuning is not the issue, it could be something as simple as a stripped B pedal nylon tuning nut on string 6.

Another common issue would be a too-loose lower return spring, allowing the lowering scissor to lift off the stop before the string has reached the desired pitch. This creates a sort of tail-chasing situation where the changer mechanism begins lowering and raising at the same time toward the end of the pull so the raised pitch is very unstable. You'll be able to see this if, when you engage the B pedal, the lowering scissor begins to lift off the stop and stretch the lower return spring mid-pull. If so you'll need to tighten the return spring if adjustable, or shorten it to increase its tension.

To answer your question about the differing length of the two pulls on 3 and 6, this is expected and is based on the diameter and relative tension of the two strings. Smaller strings require a longer pull. Modern guitars can compensate with different leverages between the bell cranks and changer to balance the pulls so they start and end at the same time. Because of its small diameter core, using a wound string on 6 will lengthen that pull so the amount of movement in the pull rods are similar, but if your guitar is currently set up for plain 6th string it would typically require some adjustment to the rodding to get the pulls timed correctly again.

Yes, the issue is just with the open string’s stability and I don’t think it has anything to do with the pedal. When I used ‘landing space’ as a metaphor, all I meant was the destination in which the harmonics of the 6th string and 8th string align seems much narrower than it does between other strings, like 3 and 4 (when tuning the 3rd string) for instance.

The amount of turn it takes at the key head for my 6th string to jump sharp over the 8th string harmonic is almost nothing, it outpaces any other tuning key/harmonics combo significantly. And it’s usually gone out of tune by the time I’ve tuned the rest of the strings.

Hope that cleared things up. The best way I can come up with to describe it is that the tension just feels off, like the string is being pulled too tightly at both ends, or there’s no give.

[J D Sauser]

a plain o.022 or o.020 on G# or A (E9th or C6th) is a) a fairly thick chunk of wire and a) on some guitars, depending on the scale length (some PSG's are have a little as 24") and also the overall length BEHIND the roller nut... namely if there is a traditional key head or a gearless/keyless tuner, which can result in a borderline "understrung" string.

When you tune up any string, you will realize that as soon as the string starts "sounding" -even thou still at a very low note- it will change pitch very fast first, but as it tenses up, it will require more and more tension to only change a half step... up to the point that you feel that it will pop just before you reach the desired note.
In other words, a string which is strung up to a note at a fairly low tension, will be more reactive to tension changes... the pedal pulls will be not just soft, but very short, where as even thinner strings return much more tension and will require a much longer pedal travel, and such an "understrung" string will also be much more reactive to bar pressure and that not only can but WILL create intonation issues... meaning that strings on the same fret under the bar will react less and thus the string pairs and chords will have tuning issues.

Many have dealt with that problem and done extraordinarily well and others have moved to a WOUND o.022 which tenses up quite "hard", but also requires a much longer and harder pedal or lever travel.

Longer scale guitars require more tension on the same string to reach the same note.

... J-D.

[Tucker Jackson]

Yes, the issue is just with the open string’s stability and I don’t think it has anything to do with the pedal. When I used ‘landing space’ as a metaphor, all I meant was the destination in which the harmonics of the 6th string and 8th string align seems much narrower than it does between other strings, like 3 and 4 (when tuning the 3rd string) for instance.

The amount of turn it takes at the key head for my 6th string to jump sharp over the 8th string harmonic is almost nothing, it outpaces any other tuning key/harmonics combo significantly. And it’s usually gone out of tune by the time I’ve tuned the rest of the strings.

I know exactly what you're talking about. It's the same on a lot of guitars where it's more difficult to get, specifically, the 6th string on its target pitch. The tuning keys are super touchy on that one, and it's because of what Lane Gray mentioned above. That string has the thickest core of all the strings so it's going to react to smaller changes in tension in an overblown way, at least as compared to other strings.

This has driven me to switch over to a wound 6th string at various points in my career. The core on that one is about half the diameter of that of the plain version, even though both strings might be listed as a gauge '022.' The thinner core of the wound translates to the tuning key being a bit less touchy, so it's easier to land on your target pitch when tuning. And it tends to stay put on that pitch a little better as you play.

There are two caveats when switching from a plain 6th to a wound one. The first is that the tone will be a little thinner and softer on the wound as compared to the plain string... and a fat pleasing tone is the reason most people stick with a plain.

And if you lower that 6th string on a knee lever, you will probably need to change the leverage under the hood since that thinner-core wound string needs a lot more travel distance to acheive the same drop in pitch. You would probably need to move the pull rod to a slot on the bellcrank that's one notch further from the axle. Easy to do on most guitars, but something to consider.

On the upside, going to a wound 6th string is easier to tune at the keyhead and it experiences less cabinet drop when you hit the A-pedal. And it experiences less cabinet raise when you use, say, the E-lower lever. In short, the wound is better for "tuning stability," for lack of a better term. So, you're looking at a trade-off... tuning stability or tone? Some people actually prefer the tone of the wound, so those lucky folks get the best of both worlds.

[Bobby D. Jones]

Is the guitar set up with a 6th string lower? If the 6th string lowers, The lower return spring must be adjusted to facilitate the lower.
If no lower on 6th make sure the 6th string lower return spring is tight enough, So does not pull the lower lever off the Changer stop bar.

Have the Nut Rollers and slots been checked for burrs on rollers sides and slots. Been cleaned and lubed and checked for smooth rolling?
Did problem start right after string change.
Check the alignment of strings over the nut rollers. It sometimes takes some special winding of strings on keys for straight line pull.
Good Luck finding the problem and cure.

[Bob Hoffnar]

Once I was sure everything was adjusted properly I switched to a wound 6th because it felt more stable. I don’t have a lower on it. Let us know what you come up with.

[Bruce Coffman]

Have the Nut Rollers and slots been checked for burrs on rollers sides and slots. Been cleaned and lubed and checked for smooth rolling?

Complete newbie here, but my first thought as well. Strongly reminds me of “nut maintenance” issues on a standard guitar… assuming that type of thing even exists on a PSG…

[Bobby D. Jones]

If the string does not move, Then you tighten a little more, And now it is high. The nut roller is not turning, Then jumping when tension on string is increased enough. The string tone will jump, From below to above your "Landing Zone".
A sticking nut roller, Will affect tuning the raise too.
Sometimes a string has to be wound toward the end of the key shaft, To keep the string straight over the nut roller. So the nut roller will not bind.
Good luck finding the problem and cure, Happy Steelin.