Blue 077 diaphragms?

[Doc Mark]

Greetings, Friends,

I have heard about "blue" 077 diaphragms, and now find out that my recently acquired L300's have 077 drivers that contain them. Being a curious sort, I got out a nice LED flashlight this morning, and shined the beam into the acrylic wedge inside the slot. A nice, blue color (looks like a ring of blue, actually) peered back at me! Why is this? What gives this diaphragm it's blue color, and it that the case with all 077/2405 drivers? If not, when and why was it changed, and is there any benefit to the "blue" ones, over the others? Thanks for any information you can send my way/ Take care, and God Bless!

Every Good Wish,
Doc

[yggdrasil]

http://audioheritage.org/vbulletin/s...lue#post163780

[Doc Mark]

Hello, Johnny.

Thanks, as always, my Friend! Interesting stuff, that's for sure! I should open up my pair of 2405's, just to see what color ring they have, but I probably won't do so. I'm glad to have one pair of 077's with the blue band, and a pair of 2405's that "are whatever they are"! Thanks, again, and God Bless!

Every Good Wish,
Doc

[grumpy]

I would recommend -not- opening them unless there is a known problem.
It is not hard to ruin the diaphragm, especially if you try to remove the phase plug
(center screw in back) ... torques surface/wrinkles foil/->->->->

(practice with a dead diaphragm)

[Doc Mark]

I would recommend -not- opening them unless there is a known problem.
It is not hard to ruin the diaphragm, especially if you try to remove the phase plug
(center screw in back) ... torques surface/wrinkles foil/->->->->

(practice with a dead diaphragm)

Howdy, Grumpy,

Many thanks for the excellent advice, and you can be sure I'll heed it. What's the old line, "don't 'fix' what ain't broke", or something like that?!! The 2405's stay as they lay, unless I ever need to repair one of them. Thanks, again, and God Bless!

Every Good Wish,
Doc