Minitaur accessory?

During the sonic state review of the Minitaur, nick used this little attenuator box to adjust the feedback loop of the headphone output into the Audio in.

One of these.
http://amazingmachines.com.br/high_res_pages/news_nastymono_release_hi.html

I’m thinking of building one that has the proper tip configuration that would still allow the added input jack to function. The one on that box is wired for the Korg products and apparently they use the tip and sleeve inverted.

Anyone done anything similar? I know there are attenuator cables out there, but I’d rather have a knob that some fiddly in-line cable.

Product development (in my head, of course) continues.

I should have specified, I have a PAIR of minitaurs coming in the mail from sweetwater. This passive potentiometer box will hopefully have a switch to swap the outputs. To Minitaur #1 will be refiltering the audio from Minitaur #2, and vice versa. With the two using slightly different patches, mixed as a stereo pair, this should be a four oscillator bass destroyer.