Zum Changer

[Adair Torres]

What is the diference between The Hybrid Changer and the Zum All Pull System Changer?
Tks.

[Erv Niehaus]

The Zum hybrid is sort of a cross between an Emmons p/p and a regular all pull changer.
It has to be tuned differently and you get some of that p/p growl.
It is an all pull changer.

[Adair Torres]

OK

[Adair Torres]

The Zum hybrid is sort of a cross between an Emmons p/p and a regular all pull changer.
It has to be tuned differently and you get some of that p/p growl.
It is an all pull changer.

So, mechanically speaking, there's no difference...? Are they both the same? Just a different tuning system...?

[Ian Worley]

So, mechanically speaking, there's no difference...? Are they both the same? Just a different tuning system...?

The hybrid changer is basically the same as a standard Zum all-pull changer, but has an added set of stop screws to allow it tune more like a PP in some respects. Those extra screws compensate to tune the interval between the open note and the longest raise like a PP, and provide direct contact between the fingers and the body/end plate in both the open and fully raised positions. The raise pulls are tuned at the keyhead like a PP, they're pulled all the way against the body. The open note is tuned with the extra screw, also like a PP. If you search google you can find the patent drawings with diagrams that illustrate how it works.

[Ian Worley]

Here is the patent: https://patentimages.storage.googleapis ... 5494A1.pdf

[Adair Torres]

Thanks Ian.
So, basically the only diference is that set of stop screws to allow it tune more like a PP ?
AT.

[Ian Worley]

Thanks Ian.
So, basically the only diference is that set of stop screws to allow it tune more like a PP ?
AT.

More or less, but it's subtly different. The solid changer mounting frame and those open tuning screws that mount in it are the primary difference. The concept is that the raise scissor is always in contact with either this solid frame/screw or the body, transferring string vibration to the body, even on a lower. I believe an intermediate raise such the the F raise on E9 string 4, or certain splits where the raise is not fully engaged would be the only exceptions. I think the basic geometry of the fingers and scissor assembly is the same as the standard Zum changer but the raise scissor is altered to accommodate the extra contact points. Bruce was really clever and innovative with his guitars through the years, perhaps he'll see this and weigh in, it's his baby.

[Paddy Long]

Here is a pic of my Red Burl D10 Zum Hybrid .... the primary raises (eg: 4th string E-F#)have a small brass hex nut on them which is fixed.
Secondary raises (eg: 4th string E - F) have the standard nylon tuning nut. (right click and open image in new tab)