I've had my Indeed for about six months or so, just read through this thread though.
I like mine a lot, but with my HD600s it gives me a headache, with two of my best, yet very different, sources. I think that:
a) I need to upgrade from the stock HD600 cable to Cardas or whatever, and
b) I just ordered a NOS JAN-Sylvania 7308 tube to replace the "Peking" 9611
So I'm looking forward to that, and that will be about for modding it as I stay away from circuit boards personally. I will solder wires and connectors, but... the attenuator project sounds good, anyways.
Anyways, I want to share my QC issues; the main thing that I noticed is there is an overall "handle with care" to this thing, from the power up/down instructions (can't have any source volume going) to the connectors themselves, as you don't want to disturb this thing while it's in operation.
The one issue I have is that the 1/4" jack is very picky, as I cannot get both channels to work properly with my Neutrik-terminated Canare headphone extension cable; it works fine with my Senns and Grados directly though, and my Planet Waves extensions.
And when it finds a permanent, non-stopgap home it will definitely get velcro'd to the surface it sits on, because this little amp is very light, and the Planet Waves connectors are quite heavy. The connectors like to tilt the amp off it's axis, making it stand on one edge, or threatening to scoot it off the table entirely