Does anyone have the internal schematic to an I 40 touch button replacement module? I guess it is some type of SCR circuit but this is just something out of pure curiosity. The ones I have seen are completely sealed. I may have some other uses for these things depending on how the circuit is wired plus I'd like to build a little tester for these things.

No I don't..Sorry..But they are wonderful..Vacumn tubes should only be used in guitar amps..LOL..

Here is one circut.

Yes I play guitar too and tubes are still the best sounding thing out there ....even in 2012.

most older touch buttons are based on the wheatstone balanced brige theory. Touch it and the bridge is unbalanced and the button fires.

I only play thru vacuum tube amps myself, preferably an old Marshall with EL34s.

Thanks E-man. I am aware how the old tube circuits worked. I just want a detailed schematic of the I40 modules. I tried downloading the two .gif file links provided by Vatorman but they contain no data. I am doing a tear out of an old Otis with an EMO and and about every other type of overlay Otis could throw at this thing until they lost the contract. I might have a couple different uses for the I40 modules. It is just a technical curiosity. Cool, another elevator man musician. I like tube amps mostly because they have the ability to clean up nicely with just a roll of your volume knob. I play through a Hughes Kettner Switchblade.