I got something to say that's a little bit embarassing for me... :-\ ...
I try my new DBA Interstellar OD with the same cable I used when I tried to plug the HH from the line out to my computer soundcard... and... my guitar made no sound at all...

... Yep, what I'm painfully trying to say is the cable is dead and I was not clever enough to try the HH with another cab..

... On a positive side, it's a confirmation I was right to not become a sound engineer !
So I try with a good cable and the HH does work well... but the sound was not very.. mmm.. nice.
It was OK when use alone in clean setting but really horrid when I tried it with any distortion device I have .
I guess I really have to try it with a cab !
Once you're lost in twilights's blue, you don't find your way. The way finds you...