[Cowboy Pinkhat]

Is it possible to add physical weight to a hifi component, for instance the Onkyo ND-S1. 
It feels rather light and moves around a bit when playing with the iPod, so maybe I can make it a bit heavier.
 
What do I use, that doesn't interfere with the electronics?
There is plenty of room:

 

[thewolf1976]

This stuff: Frost King Moretite
 
Also sound deadener sheets.

 

[Uncle Erik]

I'd be reluctant to add weight. It might interfere with cooling.

Though you might want to consider removing the feet and putting heavier ones on. Or maybe replace the feet with spacers and bolt it to an aluminum or steel plate. That would work.

But I'd be cautious about putting something heavy inside the case.

 

[mark2410]

velcro it to a base perhaps?

 

[tim3320070]

Velcro is the solution per Mark....or find a nice sized geode.

 

[fatcat28037]

X3 on the Velcro unless you're a Duct Tape kinda' guy.
 
  

 

[Pricklely Peete]

Cheap rope caulk is what I use....just use it on the parts of the chassis that are exposed (bare metal/plastic). Lay it all over the place (neatly) but not on any of the pcb's or any parts used in the circuit. It will add some heft and dampen the chassis at the same time while being very wallet friendly.
 
Peete.