Fender increased the mass in the block with the 2008 model. IMHO, this is one of the best bridge design they have ever come up with.

Yes, I seem to recall something like that too. I think the new block is "copper-infused". I wonder if that's standard on AmStd's now or just select editions.

I just swapped out my 2008 AmDlx block for the Callaham. My plan was to conduct a test, recording before and after, including wave-forms. I even built a lever contraption to control attack. I mic'd my amp and turned off the reverb. There was no affect, just straight guitar noise.

I believe the 2008 AmDlx block is 1040 steel. Moreover, its not really "cubical", if thats the right word. Its got a big corner cut off. Convwersely, the Callaham is 1080 steel and is "cubical", complete with the corner still intact. So, not only is the Callaham more dense, but its more volumous. Both of these characteristics should change its resonant properties. Somebody mentioned Fenders new blocks are more dense. I dont know if mine is the newer, denser version or the older one.

I put new strings on the guitar, tuned it to an open G and strummed in the lever contraption. Then I picked up the guitar and and picked a little, while recording. The recording went well, including the wave-form.

Next, I put the Callaham block on the the AmDlx bridge. I restrung the guitar with new strings of the same variety and set it in the lever contraption. I tuned it to open G, again, and strummed. Then I took picked the guitar, attempting to mimic my earlier picking.

But I made a mistake that adulterated my second recording (Callaham). Before starting the actual recording, I instinctively adjusted the input levels on the midi-interface. I did this because the the wave-forms were peaking out on the Callaham. What it showed, was that the sound was definately different. But because I messed with the inputs, the test was flawed. Im very pissed off about that and havent decided whether Im going to reconstruct the test.

What I can tell you is that before I jiggered with the input levels, the system was definately showing a difference in sound. The wave forms were different. The amplitude was a little variable and the sustain was longer with the Callaham, as I recall.

Further, the differences in what I heard between the two blocks was also very perceptible. To my ears, the Callaham definately changed the tone.

Notice, Im not saying it "sounded better". Whether you prefer one tone over the other is up to you. Whether that affect is worth $100 is also debatable and preferential. I am very happy with the results and would recommend the Callaham over whatever Fender block I had.