String drifting flat while depressing non related pedal

[Gerald Shaw]

I've recently converted my E9 to a C6 set up. I have a problem I can't quite figure out. When I depress pedal 5 or 6, string 4 drifts flat and out of tune. Pedals 5 and 6 do not have a pull attached to string 4. When I look at the changer at string 4 I see no movement, the bridge doesn't appear to move either. The firmer I depress pedals 5 or 6 (harder than I would during normal playing) it drifts further and further flat. I'm thinking if I can get pedal 5 and 6 to hit a firm hard stop, I might be able to fix the problem. I tried tighting the Pedal stop on pedal 6 to see if it would elimate any mush and firm up the stop, but no deal. The rest of the setup seems to be working great - but if I press both 5 and 6 together firmly I can make string 4 go WAY flat. Any help would be appreciated.

[basilh]

Mmmmm..... Let me see ?

It could be ----------->



Yep a severe case of Cabinet Drop...

[Lane Gray]

You hit on it. It's called Cabinet Drop, the stress of the pedals (and, to a lesser extent, the rods) on the cabinet, pulling adjacent strings flat.
First: try putting no more pressure than necessary on the pedals
Second, snug up every screw holding the guitar together.
Including the ones holding the changer to the guitar.
That should help a lot.

[Gerald Shaw]

I tightened the screws up - but I'm still having the de-tuning issue. My guitar is a Mullen RP. I kind of think it might be more than just cabinet drop. I don't have this issue on any of the other combinations - at least that I've noticed. This is kind of extreme , If I lean on both 5 and 6, I can get the needle to drop from half way (in tune) to about 1/4 . It's not something I can compensate for by tuning a liitle bit sharp, it's pretty bad. Thanks for the advice.

[Lane Gray]

...
First: try putting no more pressure than necessary on the pedals...

In almost every musical instrument (and skilled trade, for that matter), good techniques generally evolved to minimize fatigue, wasted effort and what we now call RSIs. I'd say mashing on the pedals is not only a waste of effort, but has ill effects on the guitar.
OR; if mashing knocks 'em out of tune, quit mashing 'em.

[Bobby D. Jones]

Sounds like cabinet drop to me to. By most C6 tunings you put a lot of pull on the 5 string. With the pedal stops being on the body of the guitar the strings stop pulling and the stop is contacted. Now you have about a 3 or 4 to 1 lever advantage on a pedal out near the center of the cabinet putting more pressure on the cabinet. A good solid straight edge with a good dial caliper attached would probably open your eyes to what is happening with to much pedal pressure. Good Luck in correcting the problem.

[Lane Gray]

You might try calling the folks at Mullen or shooting Mickey Adams a message. Perhaps they might have some tricks for taming the drop.

[Greg Cutshaw]

You can add another rod to pull up on string 4 when pedals 5 or 6 are depressed.

[Erv Niehaus]

That's why some guitars are loaded with "compensators".

[Donny Hinson]

One thing you must do is to learn to limit your pedal pressure. Use no more than is required to reach each pedals "stop". Other than that, I'd say ignore the drift unless it's severe (usually over 5 cents). If the problem is only noticed on a tuner, then learn to cope with it. But if the problem is easily causing you to play out of tune, then it might be best to get another instrument. Some guitars do have a big problem with drop, and it's easier, sometimes, to get another guitar than it is to try and fix the one you have. That's why I recommend a guitar that is stable and reliable, rather than one that is sexy, popular, or "purty".

[W. Van Horn]

John Fabian talks a bit about cab drop becoming excessive if c6 is placed on the front neck: http://bb.steelguitarforum.com/viewtopi ... c&start=25

[Tommy White]

Every pedal guitar I've ever played had some detuning. Some worse than others. No matter the brand, I've found, if the guitar is rodded correctly and the raises are balanced with the easiest leverages keeps detuning to a minimum. I have a 10 year old Mullen Royal Precision equipped with every pull one can think of on the C6th neck with just the slightest detuning if any at all. My 4th floor pedal works on both necks raising 4 strings. It is a matter of leverages unless your guitar is somehow damaged, worn or out of adjustment somewhere and I also agree with John Fabian's analogy.

[W. Van Horn]

This may be a bit off topic, but could offer insight into the OP's situation.

Mr.White, thank you for the insight. My experience has been the same re: all guitars detuning. Do you use compensators to adjust for physical detuning on your steels?

[Gerald Shaw]

One thing I failed to mention is that I did the E9 to C6 conversion myself, so it's not a pro setup. I know enough to be dangerous, but I got everything working pretty good, except for the 4th string issue. So the chances are pretty high that the excessive de-tuning is down to my amateur set up. Overall I'm pleased with how things turned out, and I don't really notice the de-tuning anywhere else.

I only mentioned mashing the pedals to highlight the fact that if I continue to depress the pedal past the point where I normally stop, I can really throw the 4th string way off- from having the needle centered to almost the far left side of the tuning range. Just to demonstrate that range of detuning that is possible. But even with normal playing pressure it's very noticeably out of tune.

THe chord that is driving me crazy is with Pedals 5 and six down, open 4th string and 1/2 step Lower on string 3. I don't hunt down out of tune notes with my tuner, this chord is really off.

For a compensating rod, I'd need 2 rods, one from pedal 5 to a raise hole in the string 4 changer slot, and another one from string 6 to a raise hole in the string 4 changer slot, right?

Thanks for all the help and suggestions on this, I'll keep working on it.