Attenuator schematic?

[12AX7]

I'm looking for a fairly transparent attenuator to build. Something that doesn't color the tone much if at all for light reduction, maybe 4-6 DB. Anyone know of a schematic for something like that which can be built with easily sourced parts cheaply? If not, do you know of a good commercially available unit thats not too expensive?

[kagliostro]

Here a couple of detailed projects

http://www.tube-town.net/diy/tt-pos/tt-posx-en.html

http://music-electronics-forum.com/attachments/7028d1258673027-attenuator-layout-final-c.pdf

a two attenuation level version

http://www.guitarplayer.com/article/power-attenuator-project/930

here a different approach (with speaker motor)

http://www.tedweber.com/atten.htm

http://www.diystompboxes.com/smfforum/index.php?topic=16235.0

but, sorry, I didn't build so I have no further info for you about response

Kagliostro