How does a piece of wood that blocks the trem system contribute or hamper tuning stability and tone?

Question

It is fairly well known that Eric Clapton used a piece of of wood to block his trem system. However, when I tried researching the why I only found what seemed to be a bunch of unsubstantiated claims (not all of them were unsubstantiated) on what it did or improved, that is, no one really offered a solid piece of evidence back their claim up. Generally these claims were, a) it improved the tuning stability and b) it changed (often positively) the tone. Accordingly, how does this piece wood improve or hamper the tuning stability? Furthermore, what changes does it make to the tone of the guitar if any? Is there other things this wood block changes?

Essentially, I am looking for answers that can give clear explanation of the pro and cons of this wood block and a explanation of the hows and whys it positively or negatively effects the guitar's tuning, tone and so forth. Physics/engineering concepts encouraged, but not required.

Answer 1

Remember the rubber band guitar you made out of a shoebox when you were a kid? When you plucked the rubber band string, the walls of the shoebox got pulled inward from the rising tension of the rubber band.

The same thing happens when you pluck a guitar string. As it is pulled and vibrating, the tension increases. As that tension increases, it causes the tremolo to dip ever so slightly.

Want to test this out? Tune your low E string perfectly. Now, bend your high E string up a step or more without plucking it, and while holding that bend, pluck the low E and see what your tuner reads.

This does not happen on a guitar with a solid tail piece.

By jamming that piece of wood into that space, the tremolo cannot dip forward and will stay put, along with the strings. A similar effect can be achieved by installing all five springs and adjusting them to maximum tension.

Now, consider the fact that when the tremolo is enabled, the string energy at the bridge is transferred to the guitar body through the pivot points of the screws, but also through the springs, to a degree, the other end of this fulcrum. Springs are not good at transferring resonance. Jamming that piece of wood in there brings all the string energy straight to the guitar body.

Does any of this really matter? From experience I can tell you yes. When you play unplugged in your bedroom. The difference is definitely noticeable. However, plug in your guitar and turn it up to an enjoyable level, you'd have to be Clapton to really care. Turn up the distortion and you really shouldn't care even if you are him.

This sproingy boingy bridge problem is much more noticeable on floating bridges like a Floyd Rose, but even that is fixable by using lighter strings and a lighter touch. Haven't heard people complaining about Jeff Beck's tone and he floats his Strat's bridge.

Answer 2

I am not a Clapton listener actually so I do not know about his approach of wooden block. It may be affecting tone by increasing the vibration on body as the strings vibrate through the bridge. By doing that, it increases the sustain and sound I think.

As you know bridge has a direct impact on a guitars tuning. If your bridge is not stable, then you will not get a good tuning too. The wooden block stabilizes the bridge by immobilizing it. But of course, you unfortunately can not use the trem bar.