Anyone got input on "hysteresis on the changer" ?

[Georg Sørtun]

I'm in the process of writing a piece about hysteresis and other PSG peculiarities.

https://gunlaug.com/contents/music/stee ... ities.html

Had parts of this as response on a Facebook group a short while ago, but all disappeared as the OP got locked out from the group.

All input welcome.

[Donny Hinson]

Personally, I don't see this as a big problem, but that may be because I choose guitars based more on their mechanical design than I do on their looks or what "name" might be attached to them. However, if this is a concern for anyone, I suppose they could serrate or groove the part of the finger that the wrapping lays against. That might help the issue somewhat.

[Marco Schouten]

The rollers in the headstock are very important in preventing hysteresis. They need to be large enough and turn without friction

[Gary Cosden]

I think you pretty much nailed it.

[Tim Heidner]

I have trouble with this on my Willy, on the 6th string lower, always wants to return sharp. I've looked at the roller and oiled it, doesn't seem to be hanging up in any way.

[Jack Stoner]

My Franklin has tunable "drop return" compensators on the strings that are both raised and lowered. These "compensate" for the hysteresis on those strings.

I don't know if the changer is actually responsible for that but it can be compensated for.

[Donny Hinson]

The rollers in the headstock are very important in preventing hysteresis. They need to be large enough and turn without friction

I agree that that's where most of the problem lies, except in keyless models. In keyed guitars, it's not only important that the rollers be free, but also that the strings are pulling in a straight line. A string that comes off the roller and then pulls to either side is almost a guarantee that you're going to have a problem. Therefore, how you string the guitar is really important.

[Fred Treece]

Well written piece, Georg.

I thought all of my tuning issues were at the keyhead. I did not know the term “hysteresis” before today. I rarely retune the changer hexnuts; only when for some reason I decide to change offsets at the keyhead. I am ALWAYS tuning the keys, every day and at least once during practice time. The open strings always seem to go out. Could be cheap strings, could be my practice room has a lot of atmospheric variability, could be my ear just doesn’t like the way the offsets effect certain changes, could be the cumulative effect of return hysteresis.

I am interested in this compensator business. Any pictures of proven devices? Does it matter whether you have a push-pull, pull-release, or all-pull?

[Georg Sørtun]

Any pictures of proven devices?

I don't have any, but have seen some here on the forum back in time. Maybe Jack Stoner or others who have PSGs with "drop return" compensators will provide some..?

Does it matter whether you have a push-pull, pull-release, or all-pull?

This form for hysteresis is independent of type of mechanics. It is the shape of bridge/changer, friction between string and changer, and length of string between hook-up point and top of changer, that matter.

The more string-length beyond the bridge-point, the more that piece of string will contract and expand with lower/raises.
My Dekleys, with short string-length between hook-up and top of changer, do not show this form for hysteresis. I have other PSGs that do show hysteresis at the changer, and they all have longer string-length between hook-up and top of changer than my Dekleys.


FYI: I'll be traveling for the next couple of days, and may not be able to respond to comments here until I've "landed".

[Jim Park]

It would be interesting to find a very accurate electronic indicator to measure changer finger travel over 100 pulls, and see exactly the difference. I’m sure there is some, maybe after a lower,

[Georg Sørtun]

It would be interesting to find a very accurate electronic indicator to measure changer finger travel over 100 pulls, and see exactly the difference. I’m sure there is some, maybe after a lower,

Changer finger repeats rotation/travel well over thousands of pulls, unless there is something wrong - wear etc - on the contact surfaces between finger and scissors, or in the scissor linkages.

The "ancient" 'light-and-mirror' measuring method will reveal any deviation in rotation … I have used that method for decades to reveal the most minute movements for components on PSGs and a whole range of other contraptions to pin-point those hard-to-find deviations.

[Bill C. Buntin]

My experience. Some all pull changers, sort of "wear in" and develop some "less than tight" or "less than perfect" return points. I first noticed this on an MSA Classic SS. I then noticed it on GFI and EMCI. The EMCI prompted me to build a device to stop it. In which I made a stationary cross shaft and used it to put tension on the changers that had hysteresis. I have drawings of it. It essentially does the same thing as the compensators. If you are interested, I can give drawings and detailed instructions on how I corrected it.

~Bill~

[Jim Pitman]

I believe the combo of larger nut rollers/smaller axel than usual is the main reson my Infinity has no hysteresis. Perhaps the use of a bearing where the raise scissor contacts finger in the changer contributes as well.

[Greg Lambert]

I play a Derby D10 and haven't noticed any hysteresis on either neck.

[Georg Sørtun]

My experience. Some all pull changers, sort of "wear in" and develop some "less than tight" or "less than perfect" return points. I first noticed this on an MSA Classic SS. I then noticed it on GFI and EMCI. The EMCI prompted me to build a device to stop it. In which I made a stationary cross shaft and used it to put tension on the changers that had hysteresis. I have drawings of it. It essentially does the same thing as the compensators. If you are interested, I can give drawings and detailed instructions on how I corrected it.

~Bill~

I am very interested in anything that works. Please share.

[Georg Sørtun]

I believe the combo of larger nut rollers/smaller axel than usual is the main reson my Infinity has no hysteresis.

Large rollers on small axle should most definitely help in reducing/eliminating hysteresis at that end.

Perhaps the use of a bearing where the raise scissor contacts finger in the changer contributes as well.

I studied the changer design in the Infinity at the TSGA back in 2010, when Frank Carter presented an "open model" along with several PSGs. He talked about "getting lucky" with the finger-angle and bearing in the contact point – bearing did not move from the initial spot on the finger during raises and lowers. Some very interesting details there.

I did not check the string-length between hook-up and bridge-point, so cannot say if short length there also played a role in eliminating hysteresis on the Infinity changer.

[Georg Sørtun]

I have finished the article: https://gunlaug.com/contents/music/stee ... ities.html , and will leave it like that for a while. Still open for inputs – especially how best to go about fixing the problem.

[Mike Scaggs]

I studied the changer design in the Infinity at the TSGA back in 2010, when Frank Carter presented an "open model" along with several PSGs. He talked about "getting lucky" with the finger-angle and bearing in the contact point – bearing did not move from the initial spot on the finger during raises and lowers. Some very interesting details there.

I did not check the string-length between hook-up and bridge-point, so cannot say if short length there also played a role in eliminating hysteresis on the Infinity changer.

I can attest to the Infinity and the fact mine has zero hysteresis. Frank has what many consider to be the all time best changer ever produced and I would have to agree. I have owned everything from Emmons to Franklin (fill in the blanks) and the Infinity is the only guitar I have personally ever owned that did not suffer from this issue. I will say I have noticed PPs seem to have escaped hysteresis as well when they are properly setup and free from a dirty changer.

My 2 Cents