Guitar questions - tension, rolling down volume...

[Alex]

I have some questions that have been on my mind for a while now... maybe someone can help.

1.
I have two guitars that are very similar, a Gibson SG and an ESP Eclipse. Both have the same scale, a tune-o-matic bridge and stoptail. They even have bone nuts. At the moment both are in the same tuning, D standard. For some reason, the string tension only feels similar if the strings on the ESP are thicker. I have 11-53s on the ESP and it feels fine. On the SG it feels good with 11-49 already (which is quite a difference on for example the A-string as well). When I used 10-46 strings in standard tuning on other guitars, the SG felt perfectly normal with just 9-42 strings.

I always felt that because of this the SG is perfect for downtuning - it keeps tension even with thinner strings, whereas I struggle to get the ESP below C# tuning (as more than a .56 string won't fit through the tuners.

Is there some explanation, why guitars so similar feel so differently in terms on string tension? I am a bit baffled by this.

2. I have changed quite a lot of potentiometers and electronics in all my guitars to higher quality ones, as I have a single channel amp and often roll down the volume on the pickups for "cleaner" sounds. I always thought that it was common knowledge that low output pickups should be the ones that sound best/clean up the most when you roll down the volume. However, to my surprise both the hot ceramic Gibson in the neck of my Voodoo LesPaul and the ceramic Duncan Design hotrail clean up much better/clearer than for example the Alnico II Gibson humbucker in my SG- even after a treble bleed mod. Could it be that more power actually helps here?

[MisterMuncher]

Different "dead string" lengths? Has the SG a noticeably longer headstock, or less straight nut-tuner travel?

[Philly Q]

I imagine there must always be a scientific explanation for different string tension - string angle behind the bridge and/or nut, length of strings in the same areas, neck pitch, neck stiffness - but they're not things you or I can easily work out.

In the case of the SG, it might be something to do with the fact that almost the whole length of the neck is free of the body, so it flexes are bit more than a Les Paul neck.  I guess maybe that makes strings feel a bit stiffer, because when you bend the strings the neck itself is "giving" a bit so you have to push harder to get the notes up to pitch.  I think that makes sense.... or perhaps not.  :?

I had a vintage (1964) SG on which the strings always felt incredibly stiff and hard to bend.  I didn't like it much, and ended up selling it.