i had an additional idea how to dampen the tubes possible because the housing of the tu-05 is just as it is.
i used this relatively strong sponge rubber made to fill the joints between window frames and walls when building a house:
i cutted four pieces out of it always slightly longer than the distance between the top of a tube and the housing above.
i used a kitchen knife and a wooden tool to cut everything parallel / right angle:
i then shaped conical holes into the pieces using the shaping tool shown bottom right:
the holes are needed for a better fit of the sponge rubber parts on top of the tubes:
here you can see the sponge rubber pieces put on top of the tubes between tubes and housing as damper (and also the foam rubber disks as damper between sockets and tubes).
how does it influence the sound - more about that after my siesta!
Edited by GermanGuy - 7/31/13 at 6:46am