[Uncle Erik]

First you have to consider that the RS-1 and GS-1000 have completely different sound signatures.

If you're looking for the RS-1 sound you will not get it with a GS-1000.

If a circumaural RS-1 is what you want, look into C pads and other options for modding the RS-1.

 

[White_Noise]

The iPod's headphone out sucks compared to other MP3 players in the first place. If you're going to spend that much money on a pair of headphones, why wouldn't you buy a portable amp?

 

[rhythmdevils]

I think the GS1000 sounds worse than the RS1 no matter what it's being powered by. But, beyond just power, the GS1000 really needs an amp just for some incredibly warm tubes to ease their freakiness...